The invention discloses a printing mechanism for manufacturing semiconductor modules and mainly relates to the technical field of semiconductor manufacturing. A clamping jaw air cylinder is fixed to a machine rack panel through a clamping jaw air cylinder seat; a pair of letter printing clamping jaws is arranged at the front end of the clamping jaw air cylinder; a laser printer is fixed to the machine rack panel through a printer bottom board; a detecting device, a display panel and an emergency shut-down button are arranged on the surface of the laser printer; the detecting device is connected with the display panel; and the detecting device comprises a temperature sensor, a humidity sensor and a smoke sensor. The whole structure of the printing mechanism and the operation process of the printing mechanism are very simple, maintenance is fast and convenient, cost is low, printing efficiency is high, the operation state of the printing mechanism can be conveniently monitored by operators, and long-term, efficient and stable operation can be ensured. The invention further discloses a working method of the printing mechanism for manufacturing the semiconductor modules.