Generally

action of constraints exists in reliability optimization design of mechanical parts. Usually

general optimum methods are adopted in reliability optimization design

so the local solution is obtained. Aimed at this situation

a new global optimum method

namely

homotopy optimization method （HOM）

was first introduced. The HOM method overcomes the defect of existing homptopy optimization method that wants to take path-tracing

and

the new HOM method can find global optimization solution without necessarily multi-time path-tracing. The result shows the model is practical and effective and its solution is global solution better than the result with general optimum method. As the method is simple

it is worthy to spread in optimum design.