The invention discloses a credit authorization method based on a plane code. The method is realized by using the plane code and a credit authorization system constructed by an electronic information terminal and an authorization platform specific to a third party. According to the method, the plane code is used as a representation form of an authorization certificate, and a plane image is formed and can be electronically transmitted, printed or even invisible; the authorization certificate is generated, transmitted and identified by the electronic information terminal; and as the plane code has double characteristics of electronic information and plane information, the electronic information terminal can switch rapidly between the plane information and the electronic information with the rapid development of the coding technology and the mobile technology, and the authorization certificate can be generated and transmitted anytime and anywhere. Asymmetrical algorithm encryption/signature is carried out on authorization information by using the electronic information terminal, and decryption/verification is carried out on a third-party authorization platform by using an asymmetrical algorithm. Thus, the credit authorization method is low in cost, convenient to use, safe and reliable.