The utility model discloses a nailing machine with a protection mechanism. Machine body, a cross beam is arranged at the top of the machine body; a transparent protective cover and a nailing head arearranged on the surface of one end of the cross beam, the nailing head is located on the inner side of the transparent protective cover, two L-shaped sliding blocks are symmetrically arranged on the surface of the inner side of the transparent protective cover, a first spring chamber is arranged in each L-shaped sliding block, and a first circular clamping block is connected to one side of each first spring chamber; a transparent protective cover is arranged outside a nailing head; under the blocking effect of the transparent protective cover, avoidance in daily use, according to the nailing machine, the problem that an operator is injured due to the fact that the operator touches the nailing head by mistake or the hand slides into the bottom of the nailing head due to misoperation is solved, the safety of the nailing machine is greatly improved, the height of the transparent protective cover can be flexibly adjusted according to the thicknesses of different cartons, and therefore protection is conducted all the time under the condition that normal sliding of the cartons into the bottom of the nailing head is not affected.