Flue gas waste heat recovery device

The invention discloses a flue gas waste heat recovery device. The flue gas waste heat recovery device comprises a main flue and a main recovery mechanism arranged on the main flue. The main flue comprises a smoke inlet pipe, a smoke recovery pipe and a smoke exhaust pipe which are arranged from bottom to top; the smoke inlet pipe and the smoke exhaust pipe are coaxially arranged; the smoke recycling pipe comprises a plurality of smoke distributing pipes which are circumferentially and uniformly distributed by taking the rotating central axis of the smoke inlet pipe as the axis; the lower end of the smoke distribution pipe is communicated with the upper end of the smoke inlet pipe, and the upper end of the smoke distribution pipe is communicated with the lower end of the smoke exhaust pipe; the main recovery mechanism comprises a heat insulation cover surrounding the recovery smoke pipe, a main water inlet pipe arranged on the upper portion of the heat insulation cover and a main water outlet pipe arranged on