In this paper, carry on a reasonable assumption on photovoltaic/thermal (PV/T) system and establish a one-dimensional mathematical model of heat pipe PV/T systems based on the low of energy conservation. Conduct a numerical simulation of the temperature of glass cover-plate and the water in a tank on a certain condition (the flow is 250L/h, volume of the tank is 50L, initial temperature of supply water is 24℃). Build a comprehensive test-bed of heat pipe PV/T system and study the influence of different conditions on the system with control variate method, such as initial temperature, the yield of circulating water and the way of water storage. Generating capacity and quantity of heat and their efficiency can be obtained by put the parameter of Tianjin typical meteorological year into the mathematical model. The results shows that the average generating efficiency of heat pipe PV/T system is 17％and the average thermal efficiency is 23.8％and that the comprehensive efficiency can reach to 40.8％.