According to the adjustable restraint parameters of an integrated child safety seat, the seat height, seatback angle and force limiter value of the seat belt were chosen as optimization variables.This integrated child safety seat has obtained a national patent.The values of injury criteria of the head, the chest and the neck were chosen as optimization goals.Approximate model of polynomial regression and multi-objective evolutionary algorithm were adopted to optimize the restraint parameters of the integrated child safety for the protection of 3-year-old, 6-year-old and 10-year-old child occupants.The results demonstrated that the effect of optimization was significant.Finally, an adaptive matching method for seats for 3~10-year-old children passengers was proposed on the basis of three optimal restraint parameters.