Flank width adjustment device of child safety seat

The invention belongs to the technical field of automotive child safety seats, and provides a flank width adjustment device of a child safety seat. The flank width adjustment device of the child safety seat comprises a seat framework, flanks, adjustment mechanisms and a rear cover plate; the flanks can transversely slide along a cross beam independently, so that flank width adjustment of the child safety seat is carried out; it is only necessary for a user to use one hand to pinch a pair of handles of the same unit of adjustment branch mechanisms towards the middle, the corresponding flank is transversely pushed by the other hand to achieve adjustment with ease, and pinching is stopped after the flank moves to an appropriate position; double-head bolts penetrate positioning through holes under the thrust effect of a return spring and keep the device in a locked state, so that the flanks are safely fixed relative to the seat. According to the flank width adjustment device, the structure is simple, adjustment is convenient and fast, the reliability is high, and the device is applicable to children of different figures.