In this paper, we introduce the approaches of cost reduction for silicon-based thin film solar cells in our institute. Firstly, we show the main works for low-cost solar cells fabrication technology, including the research on narrow band gap materials, high deposition rate and low-cost equipment. Then we present the recent research results on device quality silicon-based materials deposition process for a-Si:H and uc-Si:H. The new solar cells efficiency record obtained in our institute will also be shown. Finally, a prospect for research, industry and application of silicon-based thin film photovoltaics will be presented.