Disclosed are a battery pack and a manufacturing method therefor. The battery pack comprises: a battery module, comprising several cells, wherein the cells are electrically connected to each other, and each cell comprises an outer side face in the direction of longitudinal extension thereof; an adapter portion, for establishing mechanical and electrical connection between an electric tool and the battery pack; a holder, wherein an accommodating cavity is internally formed in the holder, and the cells are at least partially received in the accommodating cavity; and a filler, which wraps the outer side faces of the cells, is located at an inner side of the accommodating cavity and is used for transferring heat generated by the cells out of the accommodating cavity. The outer side faces of the cells are completely accommodated in the accommodating cavity, and the ratio of the length along which the filler is set in the lengthwise direction of the cells to the length of the cells is not less than 30%.