The invention discloses a hub of a cooling water pump of an engine of an automobile. The hub of the cooling water pump of the engine of the automobile is of an integral structure and comprises a hub shell. The hub shell is of a cake-shaped hollow structure, four through holes are formed in the upper surface of the hub shell and are equidistantly distributed along a circumference concentric with the surfaces of the hub shell, a columnar opening is formed in the circle center of the upper surface of the hub shell and upwardly extends along the vertical direction, and the circular section of the columnar opening and the surfaces of the hub shell are concentric circles; a portion, which is arranged between circumferences formed by the columnar opening and the four through holes, of the hub shell is downwardly sunken to form a circle of groove structure, the groove structure and the surfaces of the hub shell share the same circle centers, and a circle of bosses is further arranged on the lower portion of the columnar opening and is close to the hub shell; beveled edge structures are arranged at the edges of the inner sides of upper and lower openings of the columnar opening, a circle of side bosses with equal widths is further arranged on the outer side of the upper opening of the columnar opening, and the lower portions of the side bosses are not in contact with the bosses.