In order to solve the problems of overall low work efficiency and excessive self-weight of the marine well repair power catwalk equipment, the virtual prototype technology is combined to conduct the kinematic and dynamic simulation analysis of the mechanical structure of the marine well repair power catwalk. Based on the simulation, the genetic optimization algorithm is used, the structural dimensions of different components that can be optimized are selected as the optimization variables, and the structural optimization of the marine well repair power catwalk is achieved with the goals of the maximal processing load and the fastest processing speed. The results show that: in the structural optimization with the goal of the maximal processing load, when the safety factor is greater than 1.5, the weight of each component is reduced by 12.5% to 33.0%; in the structural optimization with the goal of the fastest processing speed, when the safety factor is greater than 1.5, the weight of each component is reduced by 16.4% to 38.0%. This virtual prototype technology analysis method provides reference for the lightweight design of other equipment structures on offshore platforms.