The invention relates to a straw incineration system capable of fully using energy generated by straw combustion. The straw incineration system comprises an incineration furnace, a water tank, a dust removing tower, an absorbing tower and a chimney; the incineration furnace is provided with a baffle plate; a cylinder is arranged on one side of the incineration furnace; the incineration furnace is provided with a stirrer; a plant ash collecting box is arranged below the incineration furnace; the incineration furnace is provided with an exhaust pipe; the other end of the exhaust pipe is connected with the water tank; the water tank includes a water tank pot and a water tank heating wall on the water tank pot; the water tank heating wall is connected with the dust removing tower; the dust removing tower is connected with the absorbing tower; and the absorbing tower is connected with the chimney. The straw incineration system can reduce emission of waste gas, reduces the waste of biomass resources, protects the environment, and improves the resource utilization rate.