The deep burial depth and high geothermal gradient of Jiyang continental rift shale oil pose significant challenges to downhole operations, where tools and instruments are highly susceptible to failure under such conditions. Therefore, studying the wellbore temperature calculation model and conducting sensitivity analysis for horizontal wells in Jiyang shale oil plays a crucial role in ensuring drilling safety and improving operational efficiency. Based on the principles of energy conservation and heat transfer, a wellbore temperature calculation model for horizontal well drilling was established. The influences of key parameters—including horizontal section length, drilling fluid flow rate, circulation time, and surface injection temperature—on wellbore temperature distribution were systematically quantified. The analysis reveals that the horizontal section length is the dominant factor affecting wellbore temperature: an increase of 2000 m raises the bottomhole temperature by 26.9 ℃. Increasing the flow rate and extending the circulation time can effectively reduce bottomhole temperature. The surface injection temperature has a more pronounced effect when the horizontal section is shorter, but its influence diminishes as the horizontal length increases. Validation via a field case demonstrates that the proposed model effectively predicts the temperature profile in shale oil wellbores. This provides a key theoretical basis for developing targeted wellbore thermal management strategies, offering significant engineering value for enhancing the safety and efficiency of shale oil horizontal well drilling.