The compliant motion of robot helps to improve its safety and stability in interactive motion, which has attracted much more attention in recent years. In this paper, aiming at a wiredriven flexible robotic joint with active and passive compliance, a decoupling compliant control method for the stiffness and position of the wiredriven variablestiffness joint is proposed, which realizes the joint position control and also achieves the uniformity of joint compliance. The stiffness model of the joint is obtained using the Jacobian matrix and the static relationship between the models. The nonlinear equations composed of the mechanical model and stiffness model of the variable stiffness device are solved with optimization method to realize the nonlinear decoupling of the stiffness and position of the variablestiffness joint. Based on the decoupling control, a torque observation method is proposed to realize the torque compensation of the joint and enhance the joint position control ability. The prototype and control system of the wiredriven variablestiffness joint were built, and simulation and experiment analysis verify the feasibility and effectiveness of the above compliant control method.