The utility model belongs to the technical field of chemical engineering, and relates to a methanol plant sulfur recovery tail gas improvement device which comprises an incinerator and a chimney connected with the incinerator. The methanol plant sulfur recovery tail gas improvement device is characterized by further comprising a waste heat boiler and a fan which are sequentially connected with theincinerator; a liquid level device connected with the shell side of the waste heat boiler is arranged on the waste heat boiler; a water supplementing valve connected with the shell side of the wasteheat boiler is arranged on the waste heat boiler; the liquid level device is communicated with the water replenishing valve; the methanol plant sulfur recovery tail gas improvement device further comprises a desulfurization and denitrification device connected with a tail gas outlet pipeline of the fan. Electric cut-off valves are arranged between the incinerator and the waste heat boiler and between the incinerator and the chimney. The system further comprises a blow-off tank connected with the shell side of the waste heat boiler. And the drainage tank is arranged on a tail gas outlet pipeline of the fan. The utility model has the advantages of small investment, less newly added equipment, small occupied area, simple operation and good sulfur recovery effect.