The utility model provides a wet desulphurization gas phase system for methyl alcohol prepared from coke-oven gas, and relates to a wet desulphurization device in the preparation of methyl alcohol via the coke-oven gas. In order to solve the problem that a body of a Roots blower is broken when a coke-oven gas compressor trips out in the existing wet desulphurization system, the gas phase system provided by the utility model mainly comprises the Roots blower, a desulphurization tower A, a desulphurization tower B and the coke-oven gas compressor which are sequentially connected; the gas phase system further comprises a subline, a transmissible pressure gauge and a remote-controlled regulating valve, wherein one end of the subline is connected with a gas inlet of the compressor; the other end of the subline is connected with a gas inlet of the Roots blower; the remote-controlled regulating valve is mounted on the subline; and the transmissible pressure gauge is mounted at a gas outlet of the desulphurization tower B. When the coke-oven gas compressor suddenly trips out, the outlet pressure of the Roots blower is balanced by switching on the remote-controlled regulating valve, so that the breaking of the body caused by the backflow of a large quantity of coal gases through the body and rapid inversion of a 8-shaped wheel can be prevented, and furthermore, the accident occurrence possibility is reduced; the target of safety production is realized.