Belonging to the field of laser shock peening, the invention in particular relates to a laser shock device capable of replacing a glass restraint layer automatically. The device comprises: a laser, afocusing lens, a light guide tube, a standby glass bin, a stepping motor, a replacement rack, a special restraint layer, a glass sheet baffle, a rubber cushion, a workpiece, an absorption layer, a waste sheet bin, a fine-tuning knob, a fine-tuning gear and a fine-tuning rack. The special restraint layer is loaded into the standby glass bin, then the stepping motor drives the replacement rack to realize replacement of a shock layer. The light guide tube can drive the pinion and rack mechanisms to realize movement by adjusting the fine-tuning knob, thus adjusting the relative position of the restraint layer and the absorption layer. After a certain number of shocks are carried out on the glass restraint layer, a computer controls the stepping motor in terms of driving the replacement rack toreplace the restraint layer, and at the same time the discarded glass sheet is pushed into the waste sheet bin. The laser shock device provided by the invention can effectively solve the problems offrangibility, troublesome replacement and high use cost of glass restraint layer, and effectively improves the working efficiency and effect of laser shock processing.