The invention discloses an ion source vacuum interconnection self-locking system adapted to a time-of-flight mass spectrometer. The system includes a microprocessor, a hatch door state switch, and a control circuit which is composed of a first vacuum solenoid valve control circuit, a second vacuum solenoid valve control circuit, and a third vacuum solenoid control circuit. The hatch door state switch has a high potential contact which is connected to a DC power source VCC and also has a low potential contact which is grounded through a resistor R1. According to the invention, the system addresses the problem of interference on working state of vacuum solenoid valves imposed by ambient noise, and puts an end to maloperation on vacuum solenoid valves. The system guarantees that when the hatch door is open, all vacuum solenoid valves are kept closed, and it is not allowed to have two out of the three vacuum solenoid valves to be open at the same time. If two out of the three vacuum solenoid valves are open at the same time, then the three vacuum solenoid valves are closed at the same time so as to protect vacuum. The apparatus greatly increases vacuum safety upon ion source in and out of a target of the time-of-flight mass spectrometer during matrix auxiliary laser analysis.