The invention relates to a battery pack frame, which comprises a movable plug-in type frame body used for the placing of battery modules, wherein the movable plug-in type frame body is mainly formed by splicing a plurality of linear cross beams, linear longitudinal beams and liner vertical beams through corner connecting pieces. According to the scheme provided by the invention, the linear cross beams, the linear longitudinal beams and the liner vertical beams are plugged in and spliced to form the movable plug-in type frame body, and according to the required size dimension of the battery frame, the linear cross beams, the linear longitudinal beams and the liner vertical beams with different length dimensions are selected and are then spliced and fixed through the corner connecting pieces, so that a battery pack has extensibility, the development of a mold is reduced, and the installation dimension requirements of different vehicle models are met; in addition, the battery pack frame is convenient to install and disassemble, and the economic benefit of the battery pack frame is improved.