Vehicle longitudinal control is one of the key core technologies in autonomous driving research. This study established a complex vehicle longitudinal dynamics model, designed appropriate control algorithms, and constructed controllers, improving control performance. Firstly, a complex vehicle longitudinal dynamics model was established considering factors such as road inclination, tire deformation, and wheel slip. Then, the adaptive method and the backstepping sliding mode control method were used to design the controller for the model, and the stability of the control system was proved. Finally, MATLAB/Simulink was used for simulation analysis of the control system. The research results indicate that the controller designed with the adaptive backstepping sliding mode method has good stability and can control the vehicle to travel at the expected speed with a minimal error. The research results can provide technical support for autonomous driving and alleviation of traffic congestion.