Abstract: In this paper an analytical method is developed. According to this method both the radius r0 of minimal basis circle of disk cam and the offset a of follower can be deter-mined by computer, and the axle center of disk cam can be shown in computer terminal. In this method, we can not only overcome the shortcoming in exiting literature that if we want to find the basis circle radius r0 the offset a of follower must be given at first, but also the pressure angle of cam mechanism can not overstep the allowable value at any time. Thus, it is solved wholly to determine the minimal size of disk cam mechanism with translating follower in accordance with allowable pressure angle.