The invention belongs to the field of gas extraction and relates to a gas extraction pipeline continuous and automatic drainage and deslagging device. The gas extraction pipeline continuous and automatic drainage and deslagging device is composed of a main device tank, a water tank, a gas extraction inlet, a gas negative-pressure extraction port, a condensing system, a pressure regulating system, a control system, a drainage and deslagging system, a water level monitoring system, a water and slag mixer, a pressure monitoring system, a separating plate guide groove and a separating plate, wherein the water tank is arranged inside the main device tank and separated into an upper tank body and a lower tank body by the separating plate; the condensing system can condense steam inside gas and collecting water into the water tank; the water level monitoring system and the pressure monitoring system are connected with a control system so that the control system can control opening and closing of the separating plate as well as pressure regulation of the pressure regulating system; water and slag can be uniformly mixed by the water and slag mixer and then drained via the drainage and deslagging system. The gas extraction pipeline continuous and automatic drainage and deslagging device is stable in system operation, high in interference resistance, convenient to arrange, full in automation and capable of saving manual operation and achieving continuous and efficiency operation.