Genetic algorithm(GA) is an algorithm used to find approximate solutions to difficult problems through the application of the principles of evolutionary biology to computer science. It can do a global search quickly. But premature phenomenon still exists in application. As a result, the searching converges earlier and the solution of the optimization cannot be got. Therefore, this paper analyzes the merits and demerits of the pseudo parallel genetic algorithm(PPGA) and discusses the optimum possibility by using PPGA, and at last, applies it to the optimization of maintenance planning for existing bridges. The experimental result has confirmed the validity of this method. Contrast to SGA, PPGA is quick in convergence. It provides a new method for existing bridges' maintenance plan.