An optimal synthesis method of an integrated link with continuous trajectory generation mechanism is proposed based on the trajectory and velocity dual object design requirement of variable speed driving link. First,under the premise of setting uniform rotation of the crank,taking the minimum position error as objective function,the planar linkage mechanism size meeting the track design requirements is optimized and calculated. Then,regarding the driving link angular velocity as variable and the minimum error of implementing mechanism velocity value as objective function respectively,the movement law of the driving link is calculated.