Objective: To counteract the organ motion caused by respiratory movement through controlling the positioning bed’s synchronous motion with the organ with the breathing sensor in body gamma knife treatment. Methods: The displacement curve of relationship between lung volume and organs in the lung was obtained by acquiring respiratory signals with the piezoelectric film respiratory sensor. Used single chip microcomputer to control stepper motor which spurts the positioning bed through the transmitter to make it move simultaneously in real time according to the law of organ motion, so as to counteract the organ motion caused by respiratory movement and thus to improve the precision of radiotherapy. Results: The experiment indicates that this method can make the steeper motor move according to the displacement curve. Conclusion: It is feasible to counteract the organ and tissue motions caused by respiratory movement by making the positioning bed reversely move in real time in accordance with the law of organ motion during radiotherapy treatment.