In order to support the maximal protection of 6-year-old children passengers based on a new integrated child safety seat which has been patented, the new integrated child restraint system parameters were optimized. And this child restraint system model has been verified. The Latin Hypercube, Orthogonal, Uniform test design and Response Surface Model method were performed to optimize and design the parameters of seat height, seat cushion depth and so on in frontal, side and rear crashes. The results indicate that the optimized injury values decrease obviously in three independent crash cases.