针对振动筛在运行过程中存在各层筛振动幅值不同的问题,对4层筛网和激励源处的塑料板进行了工况下的测试。通过加速度传感器以及基于FFT滤波的频域积分（FFT-FDI）得到塑料板的位移时程曲线,并分析其振幅特性。测试结果表明,当工作频率确定后,若采用不同刚度的塑料板会影响振动筛的振幅稳定性和筛分效果。“,”In view of different vibration amplitude of various sieving layer of vibration sieve during its operation process, the plastic board at four layers of sieving mesh and excitation source was tested in operating mode. The displacement-time curve of the plastic board was obtained via accelerator sensor and frequency- domain integral based on FFT filtering （FFT-FDI）, and its amplitude characteristic was analyzed. Test results indicates that application of plastic plates with different stiffness affected the amplitude stability and the sieving effect once the working frequency was determined.