The invention relates to an automobile rear shock absorber installing seat assembly, which comprises a rear shock absorber reinforcing plate and a rear shock absorber seat, wherein the rear shock absorber reinforcing plate comprises a planar first base panel and a first side plate, a first installing hole is formed in the first base panel, and the first side plate extends from at least one part edge of the first base panel to the outside of the plane of the first base panel, the rear shock absorber seat is arranged on the rear shock absorber reinforcing plate and comprises a planar second base panel and a second side plate, a second installing hole aligned with the first installing hole is formed in the second base panel, the second base panel and the first base panel face each other and are connected through spot welding, the second side plate extends from at least one part edge of the second base panel to the outside of the plane of the second base panel, the second side plate and the first side plate face each other, and in addition, at least one part of the second side plate is connected with the first side plate through spot welding. The automobile rear shock absorber installing seat assembly provided by the invention can effectively avoid the welding point cracking of the rear shock absorber reinforcing plate and the rear shock absorber seat caused by stress concentration.