The invention relates to a box-type inner mold of a concrete bridge panel mold. The box-type inner mold comprises panels, rib plate sets, turn buckles and set bolts. The panels comprise two bent [-shaped steel plates, and each [-shaped steel plate comprises an upper transverse face, a vertical face and a lower transverse face; chamfered faces are arranged in all bent positions of the steel plates, and the two steel plates are combined in an opposite buckling mode to form an outer shell of the box-type inner mold; the corresponding rib plate set with a supporting function is fixed to the inner side of each steel plate, and each rib plate set comprises longitudinal rib plates and transverse rib plates; each transverse rib plate is segmented into a vertical segment, an upper transverse-bent segment and a lower transverse-bent segment, the vertical segments are fixedly connected with the vertical faces, the upper transverse-bent segments, the upper transverse faces and the corresponding chamfered faces are connected and fixed, and the lower transverse-bent segments, the lower transverse faces and the corresponding chamfered faces are connected and fixed. A V-shaped notch is formed in the junction of the corresponding chamfered face and the corresponding vertical face of each transverse rib plate, and the turn buckles are arranged between the transverse rib plates of each steel plate. According to the box-type inner mold, the opening degree can be freely adjusted according to needs, the structure is simple, and disassembling and assembling are convenient.