By means of comparing the traditional and e-commerce based supply chain of chain catering enterprises, a mathematical model of the latter is given. This model is built according to costs and profits, combined with characters of supply chain of chain catering and the merits of e-commerce. By quantizing factors of all concerns, the corresponding equations are given. The optimization method of the net profit and its optimal solution are obtained by simulation experiments. In the mean time, some issues of the e-commerce based supply chain and the further description of the logistics distribution problem are presented.