The direct utilization of hydrocarbon fuel leads to the significant issue of carbon deposition and performance deterioration in solidoxide fuel cells (SOFC). It is imperative to expedite the commercialization of solid oxide fuel cells by analyzing the causes of carbon deposition and implementing measures to mitigate it. This paper presented a three-dimensional transient multi-physics coupled model for carbon deposition. The impact of various conditions and parametered on the performance of solid oxide fuel cells was investigated through simulation model calculations, aiming to assess the long-term performance of the cells. The calculated results demonstrate good agreementwith experimental findings in terms of operating voltage and carbon deposition rate. The findings indicate that an increase in carbon deposition results in decreased porosity of anode electrode material and catalyst activity. Moreover, an upward trend in carbon deposition is observed with reduced prereforming degree, increased inlet speed, elevated operating temperature, decreased operating voltage, and higherhydrogen content in the fuel. Notably, while an increase in operating temperature, decrease in operating voltage, and higher proportion ofhydrogen lead to increased carbon deposition and severe decline in electrical performance, overall battery performance improves. These results suggest a close relationship between this phenomenon and methane cracking reaction.