The utility model discloses a westernblot reaction box, which comprises a box body and a box cover, wherein, a silica gel seal is arranged in the box cover to ensure that the box body is sealed when covered with the box cover; a venthole is formed on the box cover; a cost silicone tube is connected to the venthole; a nut cap is arranged at the tail end of the micro silicone tube; and the venthole is formed on one end side of the box cover. When the box is used, firstly, a carrier film is implanted in the reaction box; reaction reagent is filled into the box through a burette and enabled to be still, and causes bubbles to rise; and then box is full of the reagent solution and covered by the box cover. When the box cover is to be put on, the micro silicone tube is opened to enable air or excess liquid to overflow from a pipeline; then the box cover is put on, and the micro silicone tube is sealed; and the reagent reacts in the seal state. When the micro silicone tube is sealed, the reaction box is in the seal state and does not leak. The reaction box of the utility model has the advantages of simple structure, lower production cost, simple operation and less required reagent, and is applicable to laboratories of various levels.