This application relates to the field of communications technologies, and in particular, to a profile download technology. In a profile download method, a primary device obtains an embedded integrated circuit card identifier (EID) of a secondary device, where the EID is used by the primary device to obtain, from a mobile operator server, profile download information that matches the EID; receives the profile download information from the mobile operator server; and sends the profile download information to the secondary device, where the profile download information is used by the secondary device to download a profile from a profile management server, and the profile is installed in an embedded UICC (eUICC) of the secondary device after the download is complete.