In the course of test, in order to avoid the friction of the end of the specimen and the ambient noise, the test result has a great influence, the threshold voltage is 3.1V, the main amplifier gain is 40dB, the **data** acquisition time interval is 0.2s, the loading mode adopts the displacement control mode to 0.002mm/s and 0.003mm/s. The test process is controlled by computer and automatically collects data.