Encryption method and device of data encryption card

The invention discloses an encryption method and device of a data encryption card, the method is applied to an encryption card system, and the encryption card system comprises a CPU subsystem used for data encryption and a hardware subsystem used for interacting with a card reading device. The CPU subsystem comprises an encryption algorithm device, and the encryption algorithm device is configured with SM2 and SM4 national cryptographic algorithms; the hardware subsystem comprises a PCI-E interface; the method comprises the following steps: when a PCI-E interface is in a connection state, acquiring an SM2 private key and an SM4 private key in response to an instruction of starting encryption; reading the instruction for starting encryption by the CPU subsystem from the PCI-E interface; based on the SM2 private key, calculating to obtain an SM2 public key; encrypting the target plaintext by using the SM4 secret key to generate a target ciphertext; encrypting the SM4 secret key by using the SM2 public key to ge