Abstract: The parallelism of optical axis of suppression sighting system is an index to achieve accurate suppression, the characteristics of which can guarantee the parallelism of the rotary mechanical axis, visible axis and laser axis.An adjustment method for optic axis parallelism of suppression sighting system utilizing the dual-optical wedge was put forward,which could make the optic axis deflect through rotating the dual-optic wedge so as to realize the parallelism calibration of every axis. The characteristics organization of the system was analyzed, the principle and method of the dual-optical wedge were introduced on focus, and the mathematics model was established.The simulation for the model was done by Matlab, the experimental setup based on the proposed method was built and tested.Result shows that the triaxial parallelism precision is all less than 0.1 mrad by using the dual-optic wedge method.