In order to explore the contribution of each design element to the overall product image form provide a reliable design guidance for designers, this study analyzed the contribution of design elements to the overall product image form, and proposed an evaluation method of design elements based on information entropy and spider chart evaluation method. Firstly, the entropy values of various design elements were calculated based on the information entropy theory to obtain their weights. Secondly, the spider chart evaluation method was used to construct the evaluation vector of product image form design elements, draw the spider chart of the elements, and calculate the equilibrium contribution coefficient and the comprehensive evaluation value of the image form. Finally, the beauty evaluation of each sample was calculated by using the product form aesthetic measure evaluation method, and the comparison and verification were conducted, which proved the feasibility of the method. Taking the front face of Audi A7 series car as the research case, the order of the equilibrium contribution coefficient and the order of the image form comprehensive evaluation were obtained after calculating, and the spider chart of the design elements of the sample image form was drawn to intuitively show the contribution and equilibrium of the design elements to each image form.Through the evaluation of design elements of product image form, the contribution of each design element to the overall product image form was quantified, which was helpful for designers to make decisions in the design of composite image products.