为保证空间惯性传感器的正常在轨运行，在发射阶段需保证测试质量固定以避免与周围电容极板的接触碰撞；到达预定轨道后再重新捕获并以最小残余线速度将测试质量释放至精确位置，保持自由悬浮状态。测试质量的捕获定位对驱动器提出高精度的要求。本文针对在太空中捕获定位释放测试质量所用的压电直线驱动器进行了设计定制与性能测试。试验结果表明：该定制的压电驱动器最小步长小于1 nm，但步长稳定性误差较大；150 V工作电压条件最大驱动力达72 N；单步行进驱动力稳定；夹持测试质量过程中，驱动力稳定，稳定性偏差为0.16%。满足捕获、定位、释放机构的使用需求。

In order to ensure the normal operation of space inertial sensors in orbit, it is necessary to ensure the test mass is fixed during launch to prevent collision with the surrounding capacitor plate. It must grab the test mass after reaching its predetermined orbit and precisely release it in its correct position with minimal residual velocity such that it remains free-floating. In this paper, a piezoelectric linear actuator that is used to grab the test mass is designed, customized and tested for performance. The test results show that the customized piezoelectric actuator can achieve a minimum step size of less than 1 nm, but the step length stability error is large; the maximum driving force at 150 V of input is 72 N; the single stepping drive force is stable; during the process of fixing the test mass, the driving force is stable and the deviation in its stability is 0.16%. These findings meet the needs of the grabbing, positioning, and release mechanisms.