The function of population isolation is stated by the analyzing the domain of attraction of local optimum. The separation among populations and the adaptive-gathering in a population are achieved by local evolution, so the multi-model function optimization is transformed to uni-modal function optimization. Combining with the (μ+1) evolutionary approach based on space ranking that has a swift convergence speed in uni-modal function optimization, the evolutionary algorithm is presented in which populations separate and genther aunction optimization,the evolutionary algorithm is presented in which populations separate and gether automatically according to domanin of attraction,The experimental result is given at the end of the paper.