Sealing performance detection assembly

The utility model relates to the technical field of leakproofness detection, in particular to a leakproofness detection assembly, and aims to solve the technical problem that sealing between an auxiliary tool and a product is difficult when the product is subjected to leakproofness detection in the background art. According to the technical scheme, the auxiliary tool comprises a product and an auxiliary tool, the product is provided with a connecting ring, a through hole and a cylindrical section, the auxiliary tool is provided with a flange, and is characterized in that the inner wall diameter of the auxiliary tool is equal to that of the cylindrical section, the inner wall of the open end of the auxiliary tool is sunken to form a coaxial annular step, and the axial length of the annular step is smaller than or equal to that of the cylindrical section; the outer diameter of the annular step is larger than the maximum distance between the through hole and the axis of the product, the cylindrical ...