Uniform sampling device

The utility model discloses a uniform sampling device. The sampling device comprises an outer shell of which the top is provided with a shielding cover, a collecting piece arranged in the outer shell, a sample injection assembly comprising a collecting sealing piece and a sample injection pipe, a drainage assembly comprising a drainage pipe and a flow blocking assembly comprising a flow limiting pipe, and an opening connected with the collecting sealing piece is formed in the collecting piece; the sample injection pipe comprises a sample injection end located outside the outer shell and a sample outlet end penetrating through the sealing piece and located in the collecting piece, the drainage pipe comprises a flow inlet end and a flow drainage end which are arranged in the collecting piece, the flow limiting pipe comprises a fixed end and a free end which are connected with the flow drainage end, and the flow limiting pipe is communicated with the atmosphere through the free end. The inverted collection part