Abstract: For the solutions of ALLSAT(all solutions of satisfiability) problem,the existing algorithms are gradually becoming not applicable with the increase of the problem size.Therefor,a clonal immune algorithm based on multi-population is presented,and it is optimized by niche and bit climbing hill methods.Herein,population diversity is maintained and algorithm convergence speed is improved.Further,the convergence of the algorithm is analyzed.All results of application to ALLSAT show that the algorithm is very effective.