Abstract: China’s silicon based heterojunction（HJT） solar cell technology has experienced rapid development in the past five years,gradually entering the industrialization stage,but it has encountered some technical bottlenecks in its development process. This paper provides a brief overview of the structure and band structure of HJT solar cells,analyzing the research progress of key technologies in HJT solar cells from the perspectives of substrate and surface velvet technology,a-Si:H thin film technology,TCO thin film technology,and metallized electrode technology. It also looks forward to the future technological research directions of HJT solar cells from the aspects of manufacturing cost,TCO thin film materials,and stacked solar cell technology. Although HJT solar cells have advantages such as simple process flow,high photoelectric conversion efficiency,low power attenuation,low temperature coefficient,and low operating temperature. However,its high manufacturing cost has led to a slow increase in its market share,and the use of copper electrodes,indium free or low indium TCO thin film technology is an effective way to reduce the manufacturing cost of HJT solar cells. Once the cost bottleneck is overcome,the future application space of HJT solar cells will be even broader.