Abstract: To solve the strong motion-coupling problem of parallel robot, a new type synthesis method for uncoupled two-translational (2T) parallel robots with one pure constraint kinematic chain was proposed. It is composed of two types of kinematic chains for these robots. One is called actuated kinematic chain that can supply driving force to the moving platform, the other is called pure constraint kinematic chain that only provides constraints to the platform. First, the structural synthesis approach for the actuated kinematic chains was presented based on the actuation wrench screw theory and the mathematical model mapping relationship between the inputs and the outputs of the mechanism. Then, the structural design of the pure constraint kinematic chains was completed in terms of the kinematic characteristics and the constraint screw theory. Finally, type synthesis of the parallel robots with the expected mobility was successfully realized according to the assembly conditions, and a lot of novel mechanisms were obtained. The degree of freedom and kinematics analysis of the new 2-RURR/RRR and 2-CPR/RPR parallel robots were performed. Their Jacobian matrices show that both mechanisms have the uncoupled kinematics characteristics. In a result, the correctness and validity of the theoretical method proposed here are verified.