In order to evaluate the exterior design of vehicles in a relatively objective way， the method of using BP neural network is proposed to evaluate vehicle exterior design after analyzing theory of artificial neural network. Based on the advantages of BP neural network such as self-learning， self-organization， self-adaption and nonlinear dynamic processing， a BP neural network evaluation model for vehicle exterior design was established. Twenty vehicle samples were selected as learning samples， and eight vehicle samples were used as test samples. The training and verification of the example of BP network were conducted using MATLAB software. The simulation results show that BP neural network is an efficient and accurate method to evaluate vehicle exterior design.