An ERC32 processor-based satellite-borne software system comprises an exception trap entry, a fault information saving module, a faulty booting identifier setting module, a fault type judgment and processing module, a soft resetting module and an interrupt return module. When an exception trap interrupt enters the exception trap entry, the faulty booting identifier setting module is called to set a faulty booting identifier as a fixed value, and the fault type judgment and processing module is called to judge the fault trap type of an ERC32 processor; if the fault trap type belongs to an unrecoverable error, then soft resetting instruction rebooting is executed; if the fault trap type belongs to a recoverable error, then interrupt return is executed; after soft resetting instruction rebooting, a main program is started, a faulty booting identifier reading module is called to read the faulty booting identifier, and a faulty booting identifier judgment module is then called to judge the faulty booting identifier. The invention solves the problem on how to save system data after the satellite-borne software is abnormal, thus enhancing the fault-tolerant ability of the satellite-borne software, and moreover, on-orbit faults can be corrected in time.