Sealing detection device for oxygen demand of surface water

The utility model discloses a surface water oxygen demand sealing detection device, which comprises a cylinder body, a sleeve, a box body and an inner sealing block, one side of the cylinder body is in hot melting connection with the box body, the other side of the cylinder body is connected with the sleeve through a thread groove, the sleeve is internally sleeved with the pipe body, the top of the cylinder body is sleeved with a pull rod in a penetrating manner, and the inner sealing block is connected with the inner sealing block. A piston block is fixed to the bottom end of the pull rod through a bolt and located in the barrel, the bottom end of the barrel is connected with a valve through a threaded groove, a hose is fixed to the bottom of the valve through a hoop, and a filter cover is fixed to the bottom end of the hose through a hoop. According to the utility model, surface water can be pumped into the cylinder body, and detection is carried out in a sealed environment in the cylinder body without bein