There are many applications for terahertz (THz) waves at different frequencies from 0.1 THz to 10 THz and different wavelengths between millimeter waves and infrared light. THz waves have attracted recent attention due to their extensive applications in detection, imaging, and communication. In terms of the properties of natural materials to THz waves, THz modulation devices have some limitations due to the natural material properties. THz metamaterials, which use periodic structures to modify the phase, amplitude, polarization, and propagation mode of THz waves, can overcome the limitations of natural materials. Compared to passive metamaterials with fixed optical properties, active metamaterials are more capable of reconfiguring and programmability. An active metamaterial can be achieved via combining metamaterial structural units with tunable functional materials. Vanadium dioxide (VO2), undergoing a metal-insulator phase transition, exhibits modulation depths exceeding 85% in electromagnetic wave transmittance from infrared to THz frequencies. Compared with other phase transition materials (i.e., GeTe), the phase transition temperature is closer to room temperature. VO2 has a promising application in active THz metamaterials due to its characteristics. This review represented the design principles and development of reconfigurable THz metamaterials based on VO2, emphasizing the structural design and performance of devices for tunable THz modulation. The structure and performance of VO2-based THz metamaterials were described.In the first part of this review, the application of VO2 in tunable THz metamaterial absorbers is represented. The phase transition of VO2 alters the equivalent resistance, capacitance and inductance of the periodic pattern via replacing the conventional surface metal patterns of absorbers with patterned VO2, resulting in tunable resonance absorption frequencies and absorption rates. Moreover, combining VO2 with different resonance patterns or other functional materials can further enhance the modulation depth and modulation frequency of THz absorbers.In the second part of this review, we discuss the application of VO2 in THz modulator devices based on the electromagnetically induced transparency (EIT) effect. The EIT effect in metamaterials is achieved via coupling "bright modes" and "dark modes" in an external field to generate a transparent window. Integrating VO2 into such terahertz metamaterials can improve the instability issue of traditional materials in exciting the EIT effect and further enhance the tunability of metamaterials. This approach also provides a feasible solution for information encryption. In addition, compared to conventional metamaterials for wavefront manipulation, the combination of VO2 and metamaterials allows a simultaneous manipulation of the amplitude and phase of THz waves, which significantly improves a holographic imaging quality and offers a design approach for THz imaging, optical encryption, optical communication, and other applications. Note that although the phase transition performance of vanadium dioxide can be adjusted theoretically, the thermal control method is susceptible to the influence of thermal diffusion from neighboring units, resulting in a thermal crosstalk. It is thus essential for future efforts increasing unit density and improving the quality of holographic imaging to integrate low thermal conductivity materials between unit structures.In the final part of this review, we introduce the use of VO2 in THz programmable metamaterials. Programmable metamaterials provide some design concepts and directions for metamaterials development. Combining VO2 with metamaterials and the hysteresis effect of first-order phase transition, VO2 demonstrates as a nonvolatile storage component in programmable metamaterials. In this approach, transition states are stored as "memory", allowing for intelligent THz electromagnetic information processing, and this memory functionality can be also used for adaptive control.Summary and prospects Despite the development of tunable THz metamaterials based on different principles, there are some challenges associated with the difficult etching of VO2 as well as the limited precision of the process. In addition, VO2 is not the most stable phase of vanadium oxide, which is greatly affected by oxygen during etching, affecting the performance of THz metamaterial devices. For future applications, power consumption and response time must be considered. It is therefore possible to achieve lower power consumption and faster thermal response time via doping vanadium dioxide or tuning the stain by the substrate to lower the phase transition temperature, although this may introduce some challenges such as a decrease in the magnitude of the conductivity change after the phase transition and a reduction in modulation depth. By contrast, it is possible to significantly improve the response time of devices by using pulsed intense laser excitation. Furthermore, machine learning and other methods can be integrated to achieve additional structural optimization. Field-programmable gate array (FPGA) controlled programmable metamaterials, which can switch different functions via changing input encoding sequences in real time, and greatly extend the application of metamaterials by dynamically manipulating electromagnetic waves. Metamaterials application and functionality will be enhanced by adding sensors to detect temperature, humidity, illumination, etc., facilitating the development of intelligent electromagnetic metamaterials with tunable properties in the future.