Abstract: Compared with the glazed PV/T system,the unglazed PV/T system has higher photoelectric conversion efficiency and obvious advantages in power output. Based on this,the water-cooled PV/T module without glass cover was proposed. The experimenta platform which is consists of PV comparison module,water-cooled PV/T module,PV/T comparison module without cooling water was built to carry out comparison experiments,in which the effects of temperature and flow rate on the electrical and thermal conversion efficiency were researched. The results show that:under the action of water cooling,the temperature of the photovoltaic panel of the PV/T module is significantly reduced,and the power generation efficiency is increased by 11.54% compared with the PV/T comparison module;the average ambient temperature is 21.7 ℃ and the average irradiance is 650 W/m~2. Under the conditions,when the flow rate is0.12 m~3/h,the electrical efficiency of the module is 17.44% ,the thermal efficiency is 19.80% ,and the overall efficiency reaches65.69%. Taking into account the electric energy consumed by the circulating pump,the water-cooled PV/T module with a surface area of1.93 m~2can store effective energy 3.72 MJ in one day.