Based on direct and converse piezoelectric effects of piezoelectric crystal, the construction principle of piezoelectric resonator and the mass sensitivity principle of piezoelectric wafer resonant frequency (Sauerbrey equation) are analyzed in this paper. According to the Sauerbrey equation,a micromass measurement system based on piezoelectric resonance is designed,and its design scheme is analyzed.To reduce the influence of environmental factors on the piezoelectric crystal detection,the system consists of a dualresonant piezoelectric crystal oscillator which uses two same quartz oscillation circuits.By the method of modular design, each of modules in the system is designed and implemented, and the performance of the system is tested.The results show that when the loading quality at the measuring end increases,the resonance frequency difference measured by the system is greater,and the experimental results are consistent with the theoretical analysis results.Compared with the linear theoretical results,the nonlinear error of experimental results is 5.5%.The system implements the transformation between the change of the piezoelectric resonant frequency and the measured micromass, and can achieve the micromass measurement.