Built-in safety door lock for preventing from insertion open

The utility model relates to a built-in safety door lock for preventing from insertion open, which can stop safety doors from being opened unnormally with plug-in cards by others. The utility model is characterized in that insertion-proof steel bars are arranged on the lock body, in the middle of a magnetic air bag sealing strip sealing and at the corresponding position of the inclined plane of a slanting lock bolt. The utility model improves the structure of the ordinary security door with a built-in mechanical lock, and adds a rigid object at the slanting lock bolt to prevent plug-in cards or change the forced direction of plug-in cards so that the purpose of preventing improper opening of the built-in safety door lock is achieved. The utility model has the advantages of reasonable design, simple structure and reliable operation.