The invention discloses gas online monitoring equipment with a water removal function, the equipment comprises a main body cylinder, connecting cylinders and a fixing block, the connecting cylinders are connected to the two sides of the main body cylinder in an embedded manner, a gas conveying pipe is connected to the middle of the left side of each connecting cylinder in an embedded manner, the fixing block is connected to the middle of the interior of each gas conveying pipe in a lap joint manner, and a trapezoidal plate is fixedly connected to the bottom of the right side of each connecting cylinder. Arc-shaped grooves are connected to the two sides of the top of the main body cylinder in an embedded mode, an arc-shaped plate is fixedly connected to the top of the right side of the connecting cylinder, and inserting grooves are formed in the arc-shaped plate and the connecting cylinder, so that the arc-shaped plate and the connecting cylinder are in embedded lap joint through the lifting column by the main body cylinder, and the main body cylinder and the connecting cylinder are better fixed; meanwhile, a small switch and a large switch are arranged, so that installation and fixation between the main body cylinder and the connecting cylinder are more convenient, and different connection modes of the two ends of the connecting cylinder are convenient for workers to carry out distinguished installation, so that the main body cylinder and the gas conveying pipe are better overlapped and fixed by the connecting cylinder, and the overlapping property of equipment is greatly improved.