A capability exposure implementation method and system, and a related device are provided. A method embodiment of the present disclosure includes: obtaining capability information of a radio access network device, configuring an API, and setting a use time limit of the API, where the API is used to provide the capability information for a second mobile edge platform; triggering a registration function to send registration information to the second mobile edge platform, where the registration information includes an identifier of the API; receiving an API request sent by the second mobile edge platform, where the API request includes the identifier of the API; detecting whether the use time limit of the API expires; and if the use time limit of the API does not expire, sending an API response to the second mobile edge platform by using the API, where the API response includes the capability information.