Abstract: Through some practical examples, this paper analysed the best parameter of the internal-combustion driven system of distributiongas system, In the specified law of motion h_T=f_T(φ) which led its soft error to the least number, the best spring rigidity, driven system rigidity and mass were calculated by using the method of optimization in the paper, As a result, the quantitative basis for evaluating or changing the size and shape of the driven system, and correctly choosing the spring rigidity can be provided.