The utility model discloses an energy-saving water heating boiler which is composed of a boiler body, a smoke pipe and a combustion sleeve. The boiler body is divided into a combustion chamber and a heating chamber through a front guiding plate and a rear guiding plate. An ash storage chamber is arranged at the bottom of the combustion chamber, a grate is arranged between the combustion chamber and the ash storage chamber, a snake-shaped coiled pipe is arranged in the heating chamber, the upper portion of the heating chamber is connected with the smoke pipe, the combustion sleeve is arranged in the smoke pipe, the lower portion of the combustion sleeve is communicated with the upper portion of the snake-shaped coiled pipe, the lower portion of the snake-shaped coiled pipe is communicated with a water return pipe on the outer portion of the boiler body, the upper portion of the combustion sleeve is communicated with a water outlet pipe, the front guiding pipe is connected with the lower wall of the boiler body, the rear guiding plate is connected with the upper wall of the boiler body, the upper portion of the boiler body is provided with a boiler opening, a boiler door is arranged on the front portion of the combustion chamber and an ash cleaning port is formed in the front portion of the ash storage chamber. The energy-saving water heating boiler is reasonable in structure, a water jacket inside the boiler is improved, the heating time of the water jacket is shortened, the heat efficiency ratio is high, the energy-saving water heating boiler saves energy and is environmentally friendly and low in manufacturing cost, and the use cost is lowered.