The invention relates to a fire distributing and banking ternary-cycle civil boiler. The problems that existing civil boilers are low in heat energy utilization rate and high in energy consumption and steel consumption are mainly solved. The fire distributing and banking ternary-cycle civil boiler is characterized in that an inner boiler body (2) with a U-shaped cross section is connected into an outer boiler body (1); the upper right portion of the outer boiler body (1) is provided with a smoke outlet (13), and a fire sealing plate (12) is connected between the top of one side of the smoke outlet (13) of the outer boiler body (1) and the inner boiler body (2); the bottom of the inner boiler body (2) is provided with a rotary fire grate (3); and the upper portion of one side wall of the inner boiler body (2) is provided with a side opening (7), and the upper portion of the side opening (7) is connected with a fire separating partition plate (10) through a rotary shaft (9). The fire distributing and banking ternary-cycle civil boiler is simple in structure, capable of saving steel during manufacturing, high in heat energy utilization rate and capable of saving energy sources.