During data collection,the experimental data such as curve of force versus displacement are usually disturbed by the environmental uncertain signals,which cause the data to drift greatly.Since the drift is stochastic,uncertain,and has distorted the real experimental curve severely,it brings lots of difficulties in analyzing the experiment results.In this paper,based on the characteristic of the stochastic disturbance signals,a three-phase digital filter arithmetic is given,in which the disturbance signals are filtered in each phase gradually,according to the different filter methods,and then the real curve is reappeared again.Two idiographic and different instances are adopted to prove the validity of the arithmetic at the end.