The invention discloses a treating and recycling device and method for inferior coal gasification wastewater and belongs to the technical field of industrial wastewater treatment. By the treating and recycling device and method, the interior coal gasification wastewater generated by pressurizing gasification of inferior coal can be sequentially subjected to steam alkaline stripping, extraction, coagulation air floatation, hydrolytic acidification, anaerobic and aerobic treatment, coagulation sedimentation, ozone contact oxidation, quick sand filtration, mechanical stirring and clarifying, multi-medium filtering, UF, RO, treatment through a concentrated water security filter, concentrated water RO treatment and recycling, and sending to a circulating water supplementing system. By the treating and recycling device and method, the problem that inferior coal gasification wastewater treatment is difficult to realize up-to-standard discharging and recycling.