Abstract: High friction and excessive torque remain common problems in extended-reach wells. Current research primarily focuses on solving wellbore trajectory design models, with limited studies on how trajectory characteristic parameters affect friction and torque. To clarify this issue, based on the lateral catenary mathematical model, a wellbore trajectory design model and a combined analysis model of friction and torque for lateral catenary wellbores were established. Through case calculations, the design effects of the lateral catenary trajectory and the traditional three-section circular arc trajectory were compared, and the influences of kick-off point depth, transition section parameters, and maximum inclination angle on the friction and torque of the lateral catenary trajectory were analyzed. The analysis indicates that compared with the circular arc trajectory, the lateral catenary trajectory exhibits lower friction during tripping out, tripping in, and slide drilling, as well as lower torque during rotary drilling. An increase in kick-off point depth increases friction. When the transition section parameters change, the friction and torque vary complexly with the build-up rate and inclination angle. In the initial stage of increasing the maximum inclination angle, the friction and torque decrease significantly, and then the decreasing trend slows down. The analysis results demonstrate that the lateral catenary trajectory has significant advantages in reducing friction and torque. Selecting a reasonable combination of trajectory parameters during design can effectively reduce the friction and torque during drilling. The research results can provide references for on-site wellbore trajectory design.