In recent years, terahertz technology has received more and more attention and has made great progress. With the development of terahertz technology and metamaterial, adjustable metamaterial absorbers applied to the terahertz band have good application prospects. Vanadium dioxide (VO2) is a typical reversible phase change material. It is insulative at room temperature and changes to be metallic when the temperature reaches 68 °C. Based on theunique properties of vanadium dioxide (VO2) in terms of phase change, a multi-layer metamaterial absorber with switchable absorption properties is proposed. The absorber is constituted by six layers, from the top layer to the bottom layer are vanadium dioxide (VO2) square ring, polyimide (PI) dielectric layer, vanadium dioxide (VO2) film layer, cross-shaped gold layer, polyimide(PI) dielectric layer, and gold film layer. When vanadium dioxide (VO2) is at the metallic state, the structure can be used as a broadband absorber. The simulation results show that the absorptance exceeds 90% between 2.3 THz and 5.3 THz, which is not sensitive to the polarization of the incident light, and the change of the incident angle has littleeffect on the absorption performance. When vanadium dioxide (VO2) is at insulating state, the structure can be used as a narrow-band absorber. The simulation results show that the absorptance exceeds 99% at 7.1 THz, achieving a perfect absorption effect, which is not sensitive to the polarization of the incident light as well. Therefore, by switching the different states of vanadium dioxide (VO2), the switching of the different absorption properties of the metamaterial absorber is realized. Moreover, it is explored that the structure has good sensing performance when vanadium dioxide (VO2) is in an insulating state and the sensing sensitivity of the structure is 200 GHz/RIU. The absorber has the advantages of switchable absorptionperformance between narrowband and broadband, and multifunctional application. The structure can play an important role in terahertz imaging, detection, communication and sensing, and other emerging terahertz fields.