Heterojunction solar cells have the advantage of high cell efficiency and show great potential in the field of solar photovoltaics. Low-temperature metallization is an important process in the manufacturing of heterojunction solar cells, which is used to form metal grids on the cell surface. Currently, low-temperature-cured silver paste combined with screen printing is widely used to achieve this. However, the high consumption of expensive low-temperature silver paste is one of the reasons for the high cost of the cells. The photovoltaic industry is working hard to improve and optimize metallization process to reduce silver consumption. This paper reviews the recent progress on metallization technologies for heterojunction solar cells, and summarizes in detail how the components of low-temperature silver paste as well as the curing process affect the overall performance. In addition, the main metallization approaches used to increase cell effectiveness are introduced and compared, including silver paste reduction strategies such as multi-busbar and pattern transfer printing technologies, and non-silver metallization strategies such as silver-coated copper and copper plating technologies. Finally, the current challenges of different metallization process for heterojunction solar cells are analyzed and their future development are also prospected.