Taking the car tire axis/radial forming drum internal tile transmission mechanism as the research object, the grey wolf algorithm and Monte Carlo method are used for robust design and optimization of mechanism parameters. Firstly, kinematic analysis was conducted on the internal tile transmission mechanism, and a kinematic model of the internal tile transmission mechanism considering the clearance of the rotating pair was established using the complex vector method. Then, taking the length of the internal tile mechanism as the design variable and the clearance and contact angle of the rotating pair, as well as the machining deviation of the rod length, as the noise factor, a robust design model of the car tire axis/radial forming drum internal tile mechanism was established with the objective function of minimizing the mean and standard deviation of the motion position deviation. The grey wolf algorithm was used to iteratively optimize and simulate it using Monte Carlo method. The results showed that after robust design, the average position deviation of the expanding drum state of the forming drum internal tile transmission mechanism was reduced by 7.2%, the standard deviation was reduced by 2.7%, and the signal-to-noise ratio was enhanced by 2.1%. This provides a new approach for the high-quality design of the tire forming drum internal tile mechanism for cars.