When patients with limb deformities wear a 6-DOF external fixator after surgery, it is impossible to accurately analyze the muscle strength of the relevant muscles to guide patients to carry out rehabilitation training. In view of the above problems, the 3D motion capture system and force measurement platform were used to collect the marker point data set and ground reaction force data of the experimental object wearing the Taylor frame, and the biomechanical simulation software Opensim was used to establish the coupling model of the human lower limb femur with the 6-DOF external fixation support, and the muscle force of the human lower limb femur with and without the 6-DOF external fixation support was analyzed and compared through Opensim. The simulation results show that: compared with the patients without the 6-DOF external fixator, wearing the 6-DOF external fixator will increase the muscle strength of the lower limb related muscles when the patients walk after surgery, and the increase is within the patient's tolerance.