Objective To study the washing methods for the piping instruments of laparoscope and prevention form biological membrane .Methods 300 pieces of the piping instruments of laparoscope select from the center of sterilization supply were random classified into 3 groups(100 pieces in each group) according to washing methods :washing by hand(group A) ,full-automation wash-ing machine(group B) and Tri-band pressurized ultrasonic washing machine(group C) .Comparing the cleanliness and ATP detec-tion fluorescence value on different methods .Results Cleanliness of group A was 85% ,ATP fluorescence detection rate was 27% ;Cleanliness of group B was 82% ,ATP fluorescence detection positive rate was 31% ;Cleanliness of group C was 99% ,ATP fluores-cence detection positive rate was 5% .The test data of group C was significantly compare with the data of group A and B . Conclusion The washing method of using tri-band pressurized ultrasonic washing machine can effectively improve laparoscopic tube cavity equipment cleaning effect and prevent form biological membrane .