Abstract: In response to the challenge of difficulty in coupling the 102-Type coupler on tight radius curves, this study focuses on the HXD2 locomotive and establishes a vehicle coupling dynamics model with detailed drawbar representation based on multibody dynamics principles. The research investigates the influence of lateral angle deviations of the drawbar on coupling performance and examines the coupling status under conditions of tight radius curves. Moreover, optimization measures are proposed for the drawbar structure to enhance the stability of coupling on tight radius curves. The results indicate that coupling speed, drawbar opening angle, and curve radius significantly affect the coupling process. Higher speeds and smaller drawbar opening angles result in greater coupling impact, especially on curves with smaller radii. Furthermore, optimization of drawbar structural parameters reduces coupling shocks. Under the conditions of 5 km/h speed, fully open drawbar positions, and a curve radius of 180 meters, increasing the gap between the buffer block and the drawbar tail frame to 3 mm reduces the maximum contact force by 64%. Increasing it to 5 mm leads to severe oscillations during coupling. Increasing the gap between the drawbar tail and the buffer block to an angle of 3.5° decreases the maximum contact force by 59%, while increasing it to 6.5° causes the drawbar angle to be unsaturated, leading to a lack of restoring torque from the buffer block. Under their coupled effect, an angle of 3.4° to 3.6° for the gap between the drawbar tail and the buffer block corresponds to the best matching effect with a gap of 2 to 4 mm between the buffer block and the drawbar tail frame.