Abstract: Similitude theory is used in the research of composite electrodeposition in this paper for the first time. Considering simultaneously the effect of factors of hydrodynamics and electrochemistry,a model describing composite electrodeposition process of solid particle with metal is established. For the composite electrodeposition process of SiC particles with Cu in acidic copper sulfate solution, values of parameters in the correlation equation established are obtained through experiment. Prediction of the codeposition amount of SiC particle in Cu -SiC composite coating is made by using the correlation equation. It is found from the results that the prediction value is close to the experimental value with deviation not larger than 6%.