In industrial automated assembling, the phenomenon of mechanical jamming often leads to an increase in contact force between parts, resulting in assembly failures. This article focuses on the assembly task of the door pin and body orifice in automotive assembling, using the admittance control method to address the issue of compliance. Influenced by admittance parameters ( elasticity, damping, and mass), the control system may exhibit varying degrees of fluctuations in steady-state error, overshoot, and response speed. To eliminate the impact of steady-state error, this article successfully addresses it using an integral optimization method based on gain scheduling. In response to the issues of overshoot and imbalanced response speed, a penalty function-based automatic tuning algorithm is proposed. By setting penalty terms, the constraints are gradually satisfied during the solution process. Experimental results show a reduction in oscillatory fluctuations of contact force from 0. 1 N to 0. 05 N, and a 50% reduction in settling time when external impedance disappears. This method successfully avoids part damage caused by oscillations and enhances compliance performance during automated assembling.