相对于NSGA而言，NSGA—II具有以下优点：1)提出新的基于分级 的快速非胜出排序算法，将计算复杂度由 降到 ，其中： 表示目标函数的数目， 表示种群中个体的数目；2)为了标定分级快速非胜出排序后同级中不同元素的适值，也为使准 域中的元素能扩展到整个 域，并尽可能均匀遍布，文献[7]提出了拥挤距离的概念，采用拥挤距离比较算子代替需要计算复杂的共享参数的适值共享方法；3)引入了保优机制，扩大了采样空间，经选择后参加繁殖的个体所产生的后代同其父代个体共同竞争来产生下一代种群，因此有利于保持优良的个体，迅速提高种群的整体水平-Relative to the NSGA is concerned, NSGA-II has the following advantages: 1) put forward based on the classification of the new fast won the sorting algorithms, will computational complexity by to, among them: said the number of the objective function, said the number of individuals in a population　2) to calibrate the order quickly won after classification in the different elements ShiZhi, also to make accurate domain elements can spread to the whole field, and even in as much as possible, the literature [7] put forward the concept of crowded distance, the crowded distance is operator instead of need to calculate the parameters of the complex sharing ShiZhi sharing methods　3) introduced the optimal mechanisms, expanding the sampling space, the choice of the individual in breeding produced with his father generation to generation individual competition to produce the next generation of population, so to keep the fine individual, rapidly improve the whole level of population