The invention discloses an improved loudspeaker box and a manufacturing method thereof. The improved loudspeaker box comprises a base body and a joint portion that is matched and connected with the base body, wherein an insertion slot for inserting the joint portion is formed in the left side end surface of the base body, a first through slot is formed in the right side inner wall of the insertionslot, a first sliding cavity is formed in the right side inner wall of the first through slot, a first dual-oblique sliding block is in sliding fit with the first sliding cavity, second sliding cavities are symmetrically formed in upper and lower inner walls of the first sliding cavity, first sliding blocks integrally arranged with the first dual-oblique sliding block are in sliding fit with thesecond sliding cavities, and a first elastic sheet is mounted between each first sliding block and the right side wall of the corresponding second sliding cavity in a pressing fit manner.