The influence of work function of transparent conductive oxide on the performance of μc-Si(n)/c-Si(p) heterojunction solar cells is analyzed by using a AFORS-HET software. The simulation results show that the work function of transparent conductive oxide has a great influence on the performance of solar cells, such as Voc and FF. When the work function of transparent conductive oxide at the interface of TCO/μc-Si:H(n) is less than 4.3 eV, the thickness of μc-Si:H(n) emitting layer is 6 nm, the work function of transparent conductive oxide at the interface of μc-Si:H(n) /TCO is greater than 5.2 eV and the transparent conductive oxide is ZnO, the TCO/μc-Si:H(n)/a-Si:H(i)/c-Si(p)/a-Si:H(i)/μc-Si:H(p )/TCO solar cell has its photoelectric conversion efficiency up to 23.78% (VOC:758.6 mV, Jsc:40.94 mA/cm2, FF:76.58%). The result shows that the performance of the μc-Si:H(n)/c-Si(p) heterojunction solar cell is closely correlated with the work function of transparent conductive oxide. Through the work function of transparent conductive oxide, the efficiency of solar cells can be improved.