The invention relates to a power generation side power ancillary service transaction system. The power generation side power ancillary service transaction system comprises a block chain transaction platform, a block chain node module and execution units. The execution units are arranged in a distributed mode and connected with the block chain transaction platform, and the block chain transaction platform is configured to achieve management on power ancillary service transactions between the block chain transaction platform and the execution units in a certain region through the block chain technology. The block chain node module is configured to be used for processing and saving the ancillary service transactions between the block chain transaction platform and the execution units or between the execution units. The management mode of a currently centralized power grid dispatching center for the power ancillary service transactions can be changed, the motility of each power plant is fully exerted, and ancillary service facilities of all the power plants are managed in an intelligent highest revenue mode of a block chain cloud platform.