Photovoltaic(PV) power generation is often located in areas with frequent sandstorms. PV modules suffer from severe dust accumulation. This reduces photoelectric conversion efficiency and affects system operation. Therefore, studying the law of ash accumulation and its influencing factors is of great significance. To study the rules and influencing factors of PV panel dust accumulation through numerical simulation, so as to provide a theoretical basis for the optimal operation of PV systems. A simplified physical model of the PV panel was constructed using Fluent software. The logarithmic wind speed distribution formula was applied to simulate the inlet velocity. A user-defined function was used to describe the particle size distribution. The effects of different dust concentrations, wind speeds and relative humidity on the dust accumulation characteristics were analyzed. The results show that dust concentration is a key factor affecting the accumulation amount. The dust accumulation increases linearly with the increase in dust concentration. The relationship between wind speed and dust accumulation follows a non-linear trend, first decreasing and then increasing. Humidity has a significant positive effect on dust accumulation, with a threshold effect. Considering the influence of factors such as dust concentration, wind speed, and humidity on PV panel dust accumulation helps to more accurately understand the dust accumulation rules of PV panels. It provides references for the design, operation, and maintenance of PV systems.