The motion and mechanical characteristics of pneumatic soft manipulators are significantly affected by their structural characteristics. At present, it is urgent to improve the support reaction force and inclination angle of the pneumatic soft manipulator. Based on the script interface provided by ABAQUS, Python script was developed to establish a parametric simulation model of gas control software drive, using the size factor as the optimization variable, linking Isight and ABAQUS, and to determine the high sensitivity influence factor of inclination angle and support reaction force by single factor test method.The normalization and weighting strategy and the evolutionary optimization algorithm were used to optimize the inclination angle and the support reaction force, thereby obtaining optimal parameter combination. The results show that the support reaction force and inclination angle are increased by 29% and 136% respectively compared with the initial value of the response. The combination of finite element calculation and multi-variable optimization of the pneumatic soft manipulator is realized and the bending deformation capacity and load capacity of the pneumatic soft manipulator are improved simultaneously.