Aviation plug is a kind of connector, originated from military industry, so it is named aviation plug for short. Aviation plug is a mechanical and electrical component to connect the electrical circuit, so its own electrical parameters are the first problem to be considered when choosing aviation plug. The correct choice and use of aviation plug is an important aspect to ensure the reliability of the circuit. Aviation plug, also known as plug socket, is widely used in various electrical circuits, and plays the role of connecting or disconnecting circuits. It is the responsibility of the manufacturer to improve the reliability of aviation plug. However, due to the wide variety and application range of aviation plug, the correct choice of aviation plug is also an important aspect to improve the reliability of aviation plug. Only through the joint efforts of manufacturers and users, can the function of aviation plug be brought into full play. There are different kinds of aviation plugs. According to the frequency, there are high-frequency aviation plug and low-frequency aviation plug; according to the shape, there are circular connectors, according to the purpose: aviation plug for cabinet, aviation plug for audio equipment, aviation plug for power supply, aviation plug for special purpose, etc. The following mainly discusses the selection method of low frequency aviation plug (frequency is below 3MHz).