The optic microsphere cavity(OMC) can store more energy because of its whispering gallery mode(WGM), so that it obtains higher quality factors(Q); The preparation method of OMC was introduced in this paper, and the coupling principle of OMC with tapered fiber was introduced and the coupling characteristic was analyzed. An OMC resonance detection system was set up and the resonance characteristic of different coupling mode was analyzed. An OMC resonance frequency tracking and locking system was designed. The frequency discrimination curve at different modulation frequency was obtained and the characteristics of absorption line and dispersive line were analyzed. The experimentally fabricated OMC has the diameter of 440 μm, the Q factor of 1.08×108 under coupling condition. The modulation frequency can significantly affect the frequency discrimination characteristics. Under low frequency modulation, the tracking and locking effect can be improved after optimizing the modulation. The study lays a good foundation for the following experiments.