Due to the safety, reliability, and high hydrogen storage density of vehicle Type-IV composite overwrapped pressure vessels (COPVs), the Type-IV COPVs are currently the preferred choice for vehicle hydrogen storage vessels. The reinforcement layer bears 80 % to 90 % of the internal pressure load, and it accounts for a significant proportion of the total cost and weight of Type-IV COPVs. Thus, the reinforcement layer is the key problem in the design and optimization of the vehicle Type-IV COPVs. Firstly, this paper proposed a design method for vehicle Type-IV COPVs considering the strength and stiffness of reinforcement layer, and created the hydrogen storage vessel scheme. Then, the stress and strain of vehicle Type-IV COPVs under working and blasting internal pressure were analyzed by finite element simulation. Finally, the genetic algorithm was used to find the best carbon fiber for vehicle Type-IV COPVs. The results show that the scheme designed by the method in this paper can meet the requirements of vehicle use; The carbon fiber modulus most suitable for car hydrogen storage bottle winding is 288.8 GPa, and the weight of the reinforcement layer is reduced by 32 % compared to the T700S carbon fiber composite wound vessel.