The invention discloses a pressing device of an engine flange bearing bush. The pressing device comprises a base, and a handle taking the shape of a Chinese character Ji, wherein the two sides of the handle are respectively fixed at the two sides of the top surface of the base through first bolts; extending ends, on the bottom surface of the base, of the first bolts are respectively fixed with a short pin and a long pin; a first opening groove is formed in one end of a bracket; the other end of the bracket is respectively fixed on the top surface and the bottom surface of the base through a second bolt and a guide block; a pressing rod is L-shaped; a middle fulcrum of the pressing rod is hinged with the bracket through a first pin shaft to form a lever structure; a second opening groove is formed in one end of a pull rod for connecting with the lower end of the pressing rod at one side of the middle fulcrum of the pressing rod through a second pin shaft; and a pressing plate and a pressing block are fixed at the other end of the pull rod through third bolts. The pressing device can reduce the influence of human factors, and improves the pressing quality and efficiency.