In order to improve the accuracy and stability of one-dimensional position sensor detector (PSD) laser micro displacement measurement, a displacement measurement experiment system is designed. The system uses PSD as the displacement detection sensor. The current to voltage (I/V) signal conditioning circuit is designed with OPA211 low noise operational amplifier. The single chip microcomputer STM32F103 is used as the controller to control the moving laser light source by the stepping motor slide, and the ADS1256 is used to collect displacement signal. The automatic displacement and displacement measurement system is realized. The experimental results show that the system has a good linearity in the range of 014 mm, the displacement measurement error is small, and the measurement error dose not exceed ±20 μm.