The invention discloses a heating furnace waste heat comprehensive utilization system. The heating furnace waste heat comprehensive utilization system comprises a steam superheater, a power generator set and a sea water desalination device. The steam superheater is arranged in a heating furnace flue. Low pressure saturated steam generated by a heating furnace evaporated cooling system flows into the steam superheater and can be heated by heating furnace smoke to form superheated steam. The power generator set communicates with fluid of the steam superheater. The superheated steam generated in the steam superheater flows into the power generator set for power generation. The sea water desalination device communicated with fluid of the power generator set. The steam discharged by the power generator set flows into the sea water desalination device for sea water desalination. The invention further discloses a heating furnace waste heat comprehensive utilization method. Through the heating furnace waste heat comprehensive utilization system and method, gradient utilization of energy of the heating furnace steam is fully achieved, excessive pressure of the steam is used for power generation, and waste heat of the steam is further used for producing fresh water.