为了测试在冲击波或爆轰波作用下各种材料样品的自由面速度随时间变化的过程，提出了一种利用法布里－珀罗(F－P)光学共振腔的选频特性进行多普勒频移绝对量的检测来连续测量飞片运动速度的方法，建立了一套基于此方法的测量装置，并利用金属箔电爆炸驱动聚酰亚胺薄膜飞片装置对所研制的F－P干涉测速仪进行了原理性实验验证。利用所研制的F－P干涉测速仪测量了飞片速度在60ns的时间内由静止加速到大于3km／s的速度的全过程，测量数据的不确定度小于5%。与其它激光测速装置相比，该干涉仪具有体积小、结构简单紧凑和成本低的特点，在爆轰物理与冲击波物理实验研究中具有较好的应用前景。

In order to measure the velocity history of the reflected surface or the internal particles velocity history of the materials under shock wave conditions,on the basis of the frequency-selecting principle of F-P optical resonator,a new type of velocity interferometer is developed,which makes use of the absolute magnitude of Doppler shift to continuously measure the moving of a flyer speed. The flyer is driven by a electric exploding foil,the magnitude of its speed can reach up to 3km/s within 60ns. Preliminary results show that the uncertainty in data is less than 5%. Compared with other laser interferometers,the lately developed thin cavity interferometer is compact,simple and low cost. So it can be widely used in the detonation and shock wave physics experimental research.