A combined mechanism, which cycloid tooth profile planetary mechanism and screw mechanism are connected in series, can convert the input-component’s high-speed rotary motion to output-component’s low-speed reciprocating linear motion. Base on that mechanism, a linear drivers was developed. And it is composed by electric motor, eccentric shaft, cycloid-plate, screw & nut, and so on. Because an intermediate transmission mode used rolling-body is applied in the contact surfaces among the kinematic pairs, the drivers’ stability and transmission efficiency are enhanced through improving kinematic pairs’ friction state and reducing parts abrasion. In the paper, it is emphasis discussed that the kinematics and main parameters’ computational method for cycloid tooth profile planetary mechanism.