Abstract: With the wide application of distributed generation in power grid, it becomes more and more difficult to manage the power grid. The over-voltage problem of the distribution network with large number of distributed generations is very serious, and virtual power plant is an effective technical means to solve this problem. Therefore, this paper proposes a transaction mechanism for auxiliary services of virtual power plants considering voltage regulation cost and reactive power reserve. Distributed power generation in the system can still generate more reactive power after the completion of active power generation. If the reactive power can be effectively utilized, the cost of voltage regulation will be greatly reduced and the overall economic benefits will be increased. Based on the multi-level collaborative virtual power plant service architecture, this paper firstly analyzes the evaluation method of reactive power generation cost. Then the price aggregation of distributed power supply is completed with the edge calculation. After that, a global clearing optimization model of ancillary service transaction considering voltage regulation cost is established. Finally, a simulation example is given to verify the effectiveness of the proposed method. The virtual power plant reactive power optimization model based on edge computing in this paper comprehensively considers the voltage regulation cost of the power grid and the comprehensive economic benefits of the virtual power plant. It will fully utilize the voltage regulation capabilities of distributed energy sources and maximize the economic benefits of all parties.