Abstract: Impedance control is an effective method to deal with contact task of robot, but this method can only guarantee the stability of system for assumed range of environments. Aiming at this problem, this paper proposes a new adaptive energy boundary method (EBM), which improves system performance by on-line estimation of control parameters, and guarantees the stability of system. Under the control method, the system can keep expected contact force stably, and have strong robustness when contact with uncertain environment. To verify the effectiveness of the proposed method, theoretical and simulation researches are conducted to pneumatic hydraulic combination compliant control system, which prove the effectiveness of the method.