In the increasing severe energy crisis, the use of solar energy to replace traditional fossil fuels becomes a consensus in worldwide due to the non-renewable nature of fossil fuels and the inability of new energy sources such as hydrogen, wind, and nuclear energy. Among the forms of solar energy utilization, dye-sensitized solar cells (DSSCs) are a research hotspot in energy development and utilization due to their low cost, abundant raw materials, high efficiency, and long service life. The photoanode is an important component of DSSCs and plays a significant role in improving the photoelectric conversion efficiency of DSSCs. In recent years, various materials and modification methods for dye-sensitized solar cells are applied to design the photoanodes for the improvement of their photoelectric conversion efficiency. Among various photoanode materials, SnO2 is an ideal candidate due to its higher electron mobility (i.e., about 125 cm2·V-1·s-1) and larger bandgap width (i.e., 3.5 eV). However, SnO2-based dye-sensitized cells still have two main challenges, i.e., the lower open-circuit voltage (Voc) (Compared to TiO2, the conduction band edge of SnO2 shifts positively by up to 300 mV, resulting in a reduced difference between the conduction band potential and the redox potential of the electrolyte); and the lower current density (The isoelectric point of SnO2 is smaller, which reduces the binding force between SnO2 and acidic photosensitive dyes, leading to a decrease in dye adsorption and thus limiting the increase in current density from the source).This review represented recent research progress on tin SnO2 photoanodes in DSSCs, emphasizing the potential application of SnO2 in DSSCs and the challenges. This review introduced the structure and working principle of SnO2-based DSSCs, and analyzed the key factors affecting the photoelectric conversion efficiency, including short-circuit current density (JSC), VOC, and fill factor (FF). This review discussed the factors influencing these parameters and focused on the current state of research on improving SnO2 photoanodes, with the methods including surface coating, composite construction, ion doping, and metal doping. Although various modification methods are developed to improve the performance of SnO2 photoanodes, the overall photoelectric conversion efficiency is still lower, restricting its widespread application in a large scale. Therefore, developing more advanced modification techniques is a necessity to further enhance the performance of SnO2 (i.e., its stability and recyclability), and facilitate its wide application in the energy field, thus providing an effective solution to alleviate the energy crisis.Summary and prospects SnO2-based DSSCs have a potential to replace TiO2 DSSCs due to their outstanding charge transport capabilities and stable optical properties. However, a lower conduction band position of pure SnO2 makes it difficult to achieve an VOC beyond 500 mV. Also, the lower isoelectric point limits dye adsorption, inherently reducing the JSC. To address the poor performance of SnO2 nanoparticles, modifications such as changing their structural morphology, surface coating, and ion doping can be employed to enhance charge transport and suppress charge recombination, significantly improving the photoelectric conversion efficiency of SnO2 cells. To date, the photoelectric conversion efficiency of cells based on pure SnO2 is 8.74%, while that of SnO2-TiO2 composite cells is 9.53%. Although these are significant breakthroughs, there is still a gap, compared to TiO2 cells (i.e., 13%). It is evident that the current density of SnO2 is able to reach a high level (i.e., greater than 20 mA·cm-2) due to the good transport performance of SnO2, compared to that of TiO2, but there is still some gaps in open-circuit voltage and fill factor.Future research aspects are as follows:1) There is a great need for a deep understanding of electron generation, transport, loss, and collection within DSSCs, but many issues remain to be resolved. For instance, the recombination mechanism of photo-generated electrons with I3- is still unclear. The complex internal electron transport process has yet to be fully explained by any model, especially under certain light intensity disturbances affecting photo-generated current and voltage (IMPS/IMVS), necessitating further detailed theoretical studies. There are many possibilities for the process of electron injection from the semiconductor film to the FTO interface, such as thermal emission and tunneling, and there is currently no suitable theory to describe this interface, requiring a further research.2) The further use of transition metals with radii that are similar to Sn4+ (such as Ti4+, W4+, and In3+) or the synergistic effect of co-doping metals can be explored to specifically improve various properties of SnO2.3) To further break through the photoelectric conversion efficiency of SnO2, it is necessary to investigate the working process of DSSCs from a microscopic perspective and optimize each part to identify the processes limiting electron transport, improve electron yield, enhance electron transport processes, and reduce electron loss, aiming to achieve the optimum photoelectric conversion efficiency.