Aiming at the problems low efficiency and difficult to plan the actions sequence of liquid bag defect inspection system,the movement characteristics modeling for action source cylinder of liquid bag defect detection system was carried out,the Runge-Kutta method in MATLAB was used to simulate cylinder movement characteristic curve.Based on the simulation results and stroke for each work step,the action time of each working step was calculated.According to the time of each work step and the defect detection process,the action sequence was designed and the sequence diagram was drawn.After analyzing the sequence diagram in detail,a simplified scheme for defect detection and sorting process and a parallel scheme for detection actions were proposed.Through these two schemes,the actions sequence was optimized.The defect detection time was recalculated after optimization.The results show that the detection efficiency increases by 41%.After optimization,high-efficiency liquid bag detection can be realized.Embedding the liquid bag defect detection system into the liquid bag production line will not affect the original production efficiency.