Double BootLoader online upgrading method based on single-chip microcomputer

The invention provides a single-chip microcomputer-based double BootLoader online upgrading method, which comprises the following steps of: equally dividing a BootLoader program and an application program into two parts by utilizing an AB swap mode of a hardware encryption engine of an S32K3 series chip, and respectively storing the two parts in a partition A and a partition B of the AB swap mode; the BootLoader program of the partition A is run, and when an upgrading request exists within the set time, the BootLoader program of the partition B needs to be upgraded; if the verification of the hash value is passed, running the application program of the partition B; when an upgrade request is received when the application program of the partition A runs, jumping to run the BootLoader program of the partition A, and sending a request service for unlocking the super administrator permission to the hardware encryption engine; and after the permission of the super administrator is unlocked, the BootLoader program