Fuente: Wipo "IOT" The invention provides a digital certificate offline secure distribution method and system for NB-IoT terminal equipment. The method comprises the following steps: logging in an IoT cloud platform through an IoT platform user client, executing a product creation operation on the IoT cloud platform, and obtaining a user identification code authorized by the IoT cloud platform; adding nB-IoT terminal equipment and an equipment identifier ID corresponding to the NBIoT terminal equipment to a created product by the IoT platform user client; enabling the IoT cloud platform to synchronize the user identification code and the equipment identifier ID to a security service platform, so that the security service platform generates a digital certificate file ciphertext of the NB-IoT terminal equipment according to the user identification code and the equipment identifier ID; a user client of an IoT platform operates on the IoT cloud platform, selects to download a digital certificate file ciphertext of related NBIoT terminal equipment, and transmits the downloaded digital certificate file ciphertext of the NB-IoT terminal equipment to a production line PC (Personal Computer) in an off-line manner, so that the digital certificate file ciphertext is decrypted on the production line PC. The decrypted digital certificate file is filled into the corresponding NB-IoT terminal equipment.