Microbial fuel cell (MFC) is a kind of device, which can transform microbial metabolic energy into electric energy and simultaneously degrade the pollutants in wastewater by electrochemical technologies. Currently, the density of output power and efficiency are low and research of MFC is still in laboratory and in developing stage. In this paper, we design a kind of novel MFC system in which the semiconductor photocatalysis cooperating with the microbial catalysis is used by connecting photovoltaic cells to the traditional MFC systems in series. Thus we achieve a "photovoltaic cells-microbial cell" new MFC system. Experiments show that open-circuit voltage, short-circuit current and maximum output power density are greatly improved in the novel MFC system when the photovoltaic cells are exposed to the illumination. Photocatalysis of the semiconductor improves the reaction rate in the cathode chamber and the anode chamber, contributes part of power to runing the novel MFC system, and provides the basis for improving the pollutant degradation rate in wastewater. It is of great significance to solve the problem of energy crisis and environmental pollution.