The influence of back surface field of microcrystalline silicon on the a-Si(n)/c-Si(p)/uc-Si(p ) heterojunction solar cell is simulated with the afors-het software at different operation temperatures. The results show that the open circuit voltage and conversion efficiency increase with the increasing of the band gap of microcrystalline silicon. The open circuit voltage, fill factor and conversion efficiency increase with the increasing of the doped concentration. The cell performance declines when the microcrystalline silicon become thicker. The corresponding best values of doping concentration and thickness change a little when the operation temperature of the cell rises. However, the corresponding best value of band gap tends to move right obviously when the operation temperature of the microcrystalline silicon back surface field increases. The experimental results provide the experimental parameters for the commercial production of solar cells.