The invention relates to a mobile terminal digital certificate electronic signature method. According to the method, based on the characteristics of public keys and private keys and on the premise of not violating the rules prescribed by the electronic signature law, for example, a private key should be generated in a user terminal and should not leave the user terminal, a private key should not be transmitted via the network, and the like, a private key is discarded and locally and discretely stored after encryption, and the cloud uses strategies such as storing the public key and certificate to ensure that the private key is not locally cracked. In the transport layer, strategies such as double key and one-time pad are adopted to ensure that important information is not intercepted and decoded in network transmission. The identity of a certificate applicant is verified through the interface of an issuing bank, the user identity verification result of the bank counter is inherited, and therefore, remote online certificate issuing is realized in the system. The method not only can ensure that all the links of certificate applying, certificate issuing, certificate storing and certificate using are safe, but also can prevent hackers and Trojans from stealing certificate files, prevent network package-capture parsing, prevent password intercepting through screen capture and prevent an algorithm from being known through software decompiling.