Improving the photoelectric conversion efficiency has been the main research direction in the development of solar cells. It is an effective technology and method to improve the efficiency of silicon film solar cells by using plasmon resonance effect. The enhanced scattering mechanism of plasmon generated by incident light at the metal/semiconductor interface increases light absorption for the active layer, thereby improving the energy conversion efficiency of solar cells. We introduce the working mechanism and basic parameters of solar cells; then, detail the research progress in improving efficiency of silicon thin-film solar cells based on metal nanoparticles and compound nanomaterials, plasmon, surface passivation, grating, and trapping structures. After comparing the effects and cost factors of different metal nanoparticles [i.e., gold (Au), silver (Ag), and aluminum (Al)] on the efficiency of the solar cell of monocrystalline silicon solar cells, the feasibility and application significance of using Al nanoparticles to enhance the performance of such solar cells are affirmed.