Based on the detailed analysis of the power collection system of offshore wind farm, establishing a mathematical model to evaluate its economy and reliability, and proposing a topology optimization mode of the power collection system of offshore wind farm based on improving single parent’ genetic algorithms. Example analysis shows that the proposed model can consider the optimization of economy and reliability in overall rapidly and at the same time get the topology optimization results. Compared with the traditional genetic algorithm, the rate of convergence is faster and better optimization results. which can provide the design of large-scale photovoltaic power station of power collection system topology with the reference.