Aimed at the problems that Symbiotic Organisms Search (SOS) algorithm is poor in convergence, low in searching precision and ease of premature convergence, a multistrategy adaptive algorithm is proposed. Firstly, according to the fitness, populations can be divided into three groups, and each group with different strategies can achieve different functions. Secondly, a hybrid search strategy based on adaptive scaling factor can make its search strategy realization of the adaptive adjustment. Finally, in order to maintain the population diversity, a mutation is utilized when the individual beyond the boundary. Experiments are conducted on the 14 benchmark functions, and the results show that the MSASOS algorithm improves obviously the performance in convergence speed, precision and global optimization.