When the customs conducts security checks on import and export goods, baggage and personnel, portable radiation detectors can be used to detect whether there are illegally carried radioactive substances or radioactive exceeding the standard. With the increasing frequency of international trade, preventing the illegal inflow or outflow of radioactive substances through customs ports is an important link to protect national security and public health. Through rapid and convenient radiation detection of goods and baggage, potential radioactive threats can be detected in time, illegal transportation and smuggling of radioactive materials can be stopped, and nuclear safety and border security of the country can be maintained.