Micromechanical resonator is widely used in accurate measurements, in which frequency modulation and amplitude modulation are two usually used techniques. Generally, the force sensitivity of mechanical resonator is mainly limited by the thermal noise. Therefore, reducing the thermal noise of measurement quadrature by squeezing the mechanical resonator can effectively improve the sensitivity of the mechanical resonator. By using a phase lock loop to lock the resonator’s vibration frequency, a specified motion quadrature of mechanical resonator is squeezed when the frequency of the mechanical resonator is modulated at twice of its resonant frequency by using an optical trap. By using a feedback loop to stabilize the measurement system, 3 dB limit of the parametric squeezing is successfully overcome and a max squeezing rate about 4.4 dB is achieved.