Abstract：In order to improve the force distribution on the crankshaft of reciprocating pump and enhance the crankshaft performance, an optimization model of the crank phase arrangement of a reciprocating pump was established based on an analysis of the force and strength of the pump crankshaft. In the model, five initial phase angles of the crank were used as design variables and the maximum bending moment of the critical sections of the crankshaft was the objective function to be minimized. Based on the simulated annealing algorithm, the crank phase arrangement was optimized and two arrangements were obtained. Furthermore, the stress and strength simulation analysis were carried out for the optimized crankshaft. The results show that the optimized crank phase arrangement allows the crankshaft to have the smallest maximum bending moment and the lowest combined bending and torsion stress. Compared with the worst arrangement, the optimal arrangement has effectively alleviated the stress of crankshaft.The method for establishing optimization model of crank phase arrangement herein is universal and applicable to the crankshaft with even more liquid cylinders(five, seven and nine cy-linders)in single or double action reciprocating pumps. The simulated annealing algorithm can optimize crank phase arrangements quickly, but also can obtain the global optimal solution and subjects to a high reliability. It provides a new approach for crank phase arrangement optimization of similar crankshafts.