Abstract: In the view of the current cam production, most of them are depend on survey data, which can easily create an error, and can also affect the operating performance. For this reason, this paper brings forward a method to reduce the error by fitting the cam profile and develop a reverse design of conjugated cams ‘ system based on Visual Basic (VB). This system takes the three transect interpolation function to smooth the main cam contour line, which can improve the continuity of the curvature, and make another cam’s contour line according to the relationship between the conjugated cams. And then Pro/E is used to make the entity structure of the conjugated cams and do the analyses of the kinematics. By the analysis of the law of the motional curves, the motional angle and laws are determined, and finally, the redesign of the conjugated cams is realized.