The safety light curtain is a safety certified light curtain product, which consists of two parts. The projector emits modulated infrared light, which is received by the receiver to form a protective net. When the object enters the protective net and the light is blocked by the object, the receiving circuit immediately responds through the internal control circuit, that is, a signal is output in the output part for emergency braking of machine tools such as punches and presses. Safety light curtains have a wide range of applications. For example, if the contact safety door is installed on the stamping equipment that needs to send and receive materials continuously, the operator needs to open and close the door frequently, which not only increases the workload of the operator, but also reduces the production efficiency. In this case, gratings and light curtains are better options. As long as any part of the body blocks the light, the machine goes into a safe state without harming the operator as the operator transports and takes material.