A three-dimension thermal model of typical polycrystalline photovoltaic (PV) module was performed in finite element software. Based on the model, the temperature distribution of the cell layer and module's thickness direction were analyzed and simulated. The effects of environmental conditions such as solar irradiance, wind speed, ambient temperature and adjacent cell interval on the temperature distribution of PV module were investigated. The temperature distribution curves showed that the solar cell layer possessed the highest temperature of 331.76 K near the solar cell center. The increasing of adjacent solar cell interval decreased PV module temperature. Wider adjacent cell interval is recommended considering the electrical power output of PV module. The results also showed that higher solar irradiance is helpful for the heat dissipation of PV module but results in higher temperature. The effect of wind speed on PV module is obvious when it increases from 0 to 1 m/s and higher wind speed is helpful for the improving of PV module electrical efficiency. Lower ambient temperature is helpful for both the heat dissipation and the improving of PV module electrical efficiency, and this effect was obvious especially under high solar irradiance and low wind speed. (C) 2014 Elsevier Ltd. All rights reserved.