Technical risks can be classified according to the definition of project risks. Usually divided into three levels: low, medium and high risk. Low risk refers to identifiable risks, and its impact on project objectives can be monitored; Medium risk refers to the identifiable risk that will have a great impact on the technical performance, cost or progress of the engineering system. This kind of risk is very likely to occur, and it is an event that is conditionally accepted and needs to be closely monitored. High risk refers to the risk that an unacceptable event with high probability will have a significant impact on the project.