Abstract: The oval body configuration based on the characteristic of mechanism and the locomotion dexterity of a bionic cockroach robot was chosen. The workspace of a single leg and the dexterity denoted by the reciprocal of condition number of the whole bodys Jacobian matrix were used to optimize and configure the parameters of mechanism. The optimal length ratios of links were decided via dexterity and reliability. The parameterization simulation model was built in ADAMS.Simulation result according with the analysis by theory indicates that the optimization and configuration are correct and suitable. This method provides a basis for the development of actual proto and the control of bionic cockroach robot. It also can be referable for the design of other hexapod robots.