The principle of F-P optical fiber stress sensor was analyzed，The Mathematical mold of F-P Optical fiber stress sensor was proposed. An elastic structure of F-P Optical fiber stress sensor and photoelectric conversion circuit was designed. APC circuit was used in the design of F-P Optical fiber stress sensor light source circuit. The APC circuit was made up of two operational amplifiers, transistor and periphery circuit, and adopted backward photorefractive feedback offset control, which used laser diode module of PD photodiode to watch the backward output optical power. A calibration test of static state characteristic for F-P Optical fiber stress sensor was made. The test indicates that the sensor has high measure precision, which can meet the requests of project measuring.