Automobile battery pack mounting assembly and automobile

The invention provides an automobile battery pack installation assembly and an automobile, the automobile battery pack installation assembly comprises an automobile body floor, a pair of doorsill beams and a battery pack box body, the pair of doorsill beams are arranged on the left side and the right side of the automobile body floor respectively, and the lower portions of the doorsill beams protrude out of the lower surface of the automobile body floor; the battery pack box body comprises a box body lower cover and box body side edge beams surrounding the box body lower cover, the box body side edge beams located on the left side and the right side of the box body lower cover are connected with the doorsill beams on the corresponding sides in the vertical direction in an opposite mode, and the inner side surfaces of the box body side edge beams are flush with the inner side surfaces of the doorsill beams. A battery pack mounting cavity is defined by the vehicle body floor, the pair of doorsill beams and the