In the synthesis of planar cam mechanisms, the designer should check the pressure angle and radius of curvature of the cam profile which involve burdensome mathematic derivation and calculation. In order to simplify the mathematic derivation and calculation, the kinematic analysis of a binary link chain is carried out and the results are then used to synthesize the planar cam mechanism with oscillating roller follower, including the calculation of cam profile, pressure angle and radius of curvature of the cam profile. A numerical example is given to verify the effectiveness of the method.