On the basis of computer automatic control theory of artificial intelligence, we use Kmeans clustering algorithm to establish mathematical model of automatic art synthesis for computer painting, and realize the computer artificial intelligence painting synthesis by using MATLAB software. In the first part we introduce the intelligent control system of computer drawing in detail, and do decomposition and combination on the frame number by using the computer intelligent drawing cell. In the second part we establish the intelligent clustering model of Kmeans algorithm, and introduce the model painting synthesis. In order to verify the availability and reliability of the model designed in this paper, we design simulation experiment of MATLAB drawing synthesis, and obtain the art synthesis of clothing abstract drawing by calculation. It provides the theory reference for the research on computer artificial intelligence control technology