Abstract: With the growing installed capacity of offshore wind farm, the topology of wind power collection system for wind farms will become the key factor that affects the reliability and the economy of offshore wind farms, and the reliability and economy evaluation method of the wind power collection system for wind farms is proposed in this paper. Considering multiple failures of the electrical components in the wind power collection system, the reliability of different topological structures of the system is compared by using the block enumeration method, and such reliability indexes of the system as insufficient expected energy and equivalent availability of the system and the operation capacity probabilistic model of wind farm under different topologies are calculated. Furthermore, considering the impact of system reliability on economy, the once capitalized cost and failure opportunity cost are comprehensively analyzed, and economic indexes of different topologies are calculated. It can be analyzed from case that the reliability of the unilateral ring topology is the highest, and the topology of the radial topology is the most economical. Compared with the previous studies on the reliability and economy of topologies of wind power collection systems, the multiple failures of electrical components are considered in this paper, and the probability model of wind operation capacity under different topological structures is obtained. The evaluation results are accurate and reasonable, and the research has broader significance.