According to the integrant part and balanced relation of enterprise competitiveness, based on the selection principle of the evaluation index system for the enterprise competitiveness, we structure the evaluation index system of the competitiveness of Small and Medium Enterprises from five aspects: influences on district, management ability, sustainable development ability, technological innovation ability and technical strength. We used AHP to confirm the weight, established mathematical model by the integrated method, evaluated the competitiveness of Small and Medium Enterprises.