There are many medium and small towns in the north of China, and these districts are hard to be covered by main line of energy supply, particularly heating power supply. Hot-water boiler is the common equipment to meet heating demand which is installed around the town. This paper presents an integrated multi-energy supply system which uses low temperature exhaust heat of sewage, abandoned wind and photovoltaic power, coal-fired chemical energy. In heating season, the heat-supply water is heated by sewage source heat pump first, and then heated by exhaust steam of coal-fired unit. The low cost abandoned wind and photovoltaic power can be used to extract heat from sewage by sewage source heat pump, so the capacity of coal-fired unit can also be reduced. This system can make use of much renewable energy and reduce fossil energy consumption and it is a beneficial reference to implement low-carbon energy supply for medium and small cities and towns in the north of China.