According to the characteristics of series and parallel mechanism, a novel mixed-connection manipulator was designed. Its moving platform had three translational and one rotational degree of freedom. There was a subsidiary chain between the virtual fixing platform and the moving platform, which had an independent rotational degree of freedom. Compared with the parallel mechanism of the same kinematic characteristics, the workspace of the manipulator was large and its rotational degree of freedom was flexible. The manipulator was investigated and the closed-formed solutions of both the inverse and direct kinematics were developed. The velocities and accelerations were studied by using the method of kinematic influencing coefficients. The dynamic simulation was conducted, which verified the correctness of the theoretical inference.