In order to realize the small error attitude transformation of a free floating space robot, a new method of three degrees of freedom(DOF) attitude transformation was proposed for the space robot using a bionic joint. A general kinematic model of the space robot was established based on the law of linear and angular momentum conservation. A combinational joint model was established combined with bionic joint and closed motion. The attitude transformation of planar, two DOF and three DOF is analyzed and simulated by the model, and it is verified that the feasibility of attitude transformation in three DOF space. Finally, the specific scheme of disturbance elimination in attitude transformation is presented and simulation results are obtained. Therefore, the range of application field of the bionic joint model has been expanded.