Electron transport layer is a key part for perovskite solar cell (PSC), which can block holes and transmit electrons to reduce recombination. In this study, SnO₂ was synthesized with low-temperature solution-processed method and used as electronic transport layer for perovskite solar cells. The influence of annealing temperature on the properties of SnO₂ films and PSCs were systematically studied. The results showed that with the annealing temperatures at 60, 90, 120, 240 ℃, the surfaces of SnO₂ films own more pores; while annealed at 150, 180, 210 ℃, the corresponding surfaces show fewer pores. It was found that the transmittance of FTO glass covered with SnO₂ films is better than that of the bare FTO glass. With SnO₂ annealed at 180 ℃, the electron mobility of the thin film is the highest. The corresponding PSC possesses the best transmission resistance, composite resistance, and superior photovoltaic performance. The photoelectric conversion efficiency, the open-circuit voltage, the short-circuit current and the filling factor were 17.28%, 1.09 V, 20.91 mA/cm² and 75.91%, respectively.