The present invention provides an access method and system of a customer premise equipment, and a broadband network gateway. The access method of a customer premise equipment includes: receiving, by a BNG in a BNG pool, an access request packet sent by a CPE, where the access request packet carries an identifier of a CPE group to which the CPE belongs; and obtaining, by the BNG, an access policy of the CPE group according to the identifier of the CPE group, and performing access control on the CPE according to the access policy. Through the present invention, a BNG in a BNG pool is enabled to provide an access service for a CPE according to an access policy, so that when a BNG in a BNG pool is faulty, a BNG that is not faulty in the BNG pool can provide an access service for a CPE originally accessing the faulty BNG, thereby improving the reliability of the entire network.