Abstract: To address the safety issues of drilling in deepwater formations with natural gas hydrates, the influence of drilling on pore pressure in formations with natural gas hydrates was studied. Based on the wellbore-formation heat transfer theory, an excess pore pressure calculation model incorporating methane solubility was established, and the accuracy and reliability of the model were verified using the TOUGH+HYDRATE (T+H) program. Case studies were conducted to analyze the influence law of initial natural gas hydrate saturation, initial pore pressure, and initial permeability on excess pore pressure. Through the T+H programs, the evolution characteristics of pore pressure in formations with natural gas hydrates under wellbore temperature variations were investigated, and the influence mechanism of wellbore temperature on the formation excess pore pressure was analyzed. The results indicate that the trend of excess pore pressure changes is highly consistent with the development of gas saturation. Moreover, the higher the wellbore temperature, the longer the risk duration and the wider the affected range associated with excess pore pressure, making it essential to implement appropriate thermal insulation measures. The research findings can provide a scientific basis for predicting and quantitatively analyzing the decomposition risks of natural gas hydrate, and offer guidance for risk assessment and mitigation strategies in deepwater engineering projects.