Thermal performance analysis and cryogenic experiment of the 650 MHz cavity prototype cryomodule for the circular electron-positron collider

•The 650 MHz cavity prototype cryomodule has been designed, constructed and commissioned.•The thermal performances analysis based on the thermo-electrical analogy are performed.•The theoretical calculations and experimental measurements were compared.•The thermal calculation model of the gas-cooling coupler is developed and verified by experiments in the SHCS.