The invention provides a photovoltaic member heat-transfer coefficient testing device and a method thereof. The testing device comprises an indoor case, an outdoor case, a test piece frame, a filling plate, an electrothermal membrane member, a wind-separating board, a blower fan, a first evaporator, a second evaporator, a first electric heater, a second electric heater, plural temperature sensors, an environment space case, an air conditioner, a first humidity-control apparatus, a second humidity-control apparatus, an electrothermal membrane power supply, and a control and data acquisition system. The electrothermal membrane member comprises an electrothermal membrane, a panel and a backboard, the upper and lower surfaces of the electrothermal membrane are adhered with the panel and the backboard by an EVA adhesive layer; the plural temperature sensors are uniformly distributed on the electrothermal membrane, and the thermocouples are connected with the control and data acquisition system. The device and the method overcome the disadvantage that the current technology cannot test the heat-transfer coefficient under photoreceptive power generation state, and can provide reference for testing heat-transfer coefficient of an inner heat source building enclosing structure.