Abstract: To address the difficulties in the development of robotic rescue equipment, the structural parameters of the snake-like robot with a function of muscle injection are optimized, to deal the problem of constraints of the non-structural environment of debris on the robot's task performance. Firstly, a model of the robot's motion performance as a function of structural parameters is established, based on the analysis of the robot's motion mechanism in the environment of debris. Then, the models are solved separately using two approaches, NSGA-II based on non-dominated ranking, and MOEA-D multi-objective genetic algorithm based on decomposition. By comparing the two approaches, it is demonstrated that NSGA-II is more effective in solving the model, and the optimization structural design parameters of the robot prototype are finally determined. Lastly, a prototype of snake robot is developed for experiments according to the optimization results. Experimental results show that on the robot, the maximum step-overcoming height is 0.18m, with a relative error of 0%; the maximum gully-crossing width is 0.4m, with a relative error of 2.3%; and the minimum steering resistance torque is 14.320N.m in the linear configuration, with a relative error of 11.2%. The effectiveness of the NSGA-II-based multi-objective optimization design method for the structural parameters is verified.