In order to overcome the shortages of detection of quartz crystal specific rotary power measurement by rotate polarizer method,these shortages are big error,low precision and poor practicability etc.Put forward a measurement for quartz crystal specific rotary power measurement based on liquid crystal variable retarder (LCVR).Change the driving voltage of liquid crystal variable retarder,accurately control the liquid crystal phase retardation,and modulate the polarized light.By measuring the Stokes parameters according to polarization modulation method,real-time and accurate measurement for quartz crystal specific rotary power is done.Detection of polarized light signal using PIN photodiode,after the photoelectric conversion,signal conditioning circuit is used to achieve signal processing,signal collection etc.Process collected data and display.The experimental results show that the method measurement accuracy is 0.57%.