The invention discloses an efficient energy-saving rotary waste fuel water heating furnace which comprises a water inlet pipe, a shell, a smashing machine, a rotary drum, smashing knives, a combustionfurnace, an air inlet pipe, a rotary circular table, a heat exchange pipe, an air outlet pipe and a water outlet pipe. The combustion furnace is arranged inside the shell, a rotary motor is arrangedat the bottom end inside the combustion furnace, an output shaft of the rotary motor is connected with a rotating shaft, the top end is provided with the rotary circular table, air holes are evenly formed in the rotary circular table, the upper surface of the rotary circular table is provided with multiple electronic igniters, the rotary drum is arranged inside the smashing machine, the outer wallof the rotary drum is evenly provided with the smashing knives, the top end of the combustion furnace is provided with a secondary igniter, the top end of the combustion furnace is connected with oneend of the heat exchange pipe, the other end of the heat exchange pipe communicates with the air outlet pipe, the outer wall of the combustion furnace is wound by the heat exchange pipe, and the outlet end of the air outlet pipe is provided with gas spray head, The heating effect is improved, energy waste is avoided, energy is greatly saved, heat loss is reduced, the energy utilization rate is improved, the structure is simple, use is convenient, energy is saved, and popularization is facilitated.