Abstract: The invention discloses a mobile phone subscriber identity card on multichannel digital authentication of mobile payment, including a card body and an in-card circuit integrated in the card body. The in-card circuit includes an MCU security chip; one or more digital authentication certificates are stored in the MCU security chip, and a digital certificate authentication processing module for authentication of the digital authentication certificate is provided; the in-card circuit includes a data link for transmitting data of the digital authentication process; the digital certificate authentication processing module is connected to the mobile phone terminal through the data link, and to a third-party authentication institution through a network resource of the mobile phone terminal online, to conduct digital certificate authentication.