Mechanical optimization design is a new design method in the development foundation of the modern mechanical design theory, the traditional design repeats the analysis of product performance passively and doesn’t design product parameters actively, which often cost too much money and manpower, and the application of optimization design in mechanical design can make the scheme achieve some optimization results in the design requirements specified, without consuming too much computational effort. Through the concrete examples, introduces the steps and method of setting up mathematical model of the mechanical optimization design. A brief overview of some optimization algorithm, such as genetic algorithm, artificial neural network, simulated annealing algorithm, Ant algorithm, tab search algorithm, particle swarm algorithm and hybrid algorithm combined some of them. The corresponding mathematical models of algorithm are established, according to the actual mechanical design problems, and used to solve the established mathematical model by computer, so as to obtains the optimal design scheme.