Terahertz (THz) imaging based on the terajet (TJ) effect has demonstrated significant potential in various fields. However, achieving high-resolution imaging with an extended depth of field (DOF) remains a challenge. In this study, we report a mesoscale Bézier Curve structure (BCS), whose curved surface is defined by a second-order Bézier curve, to manipulate the characteristics of TJs and realize extended DOF in subwavelength resolution imaging. The tuning of the TJs’ focal distance, effective length, and full width at half maximum by adjusting the control points of the Bézier curve were confirmed both numerically and experimentally. Imaging experiments showed that a DOF of approximately 7λ was achieved while maintaining subwavelength resolution, and the BCS-coupled imaging system effectively resolves samples at different depths. This flexible, practical, and cost-effective method for achieving extended DOF holds great potential for THz high-resolution imaging and detection, especially in scenarios involving samples of finite thickness.