A method of registration and access control of identity for third-party certification is provided. The method has steps of registration and steps of access control. The steps of registration have: controlling a user-end computer apparatus to retrieve an identity image of an identity document of a user; executing processes on the identity image for obtaining identity data; retrieving embedded identity data from the identity document; and configuring and registering the identity data if the data are matched with each other. The steps of access control have: controlling the user-end computer apparatus to verify user's identity upon reception of request of identity access, and generating and returning return identity data to a request-end computer apparatus.