Primary load power supply system

The utility model discloses a primary load power supply system, and the system comprises a first bus which is electrically connected with a plurality of first commercial power loads and a plurality of first emergency loads; the second bus is electrically connected with a plurality of second commercial power loads and a plurality of second emergency loads; the mains supply supplies power to the first bus and the second bus; the emergency power supply is electrically connected with the second bus, and an outgoing circuit breaker is arranged between the emergency power supply and the second bus; and the commercial power bus tie switch is arranged between the first bus and the second bus, the plurality of first emergency loads and the plurality of second emergency loads are in one-to-one correspondence, and the plurality of first emergency loads and the plurality of second emergency loads are standby for each other. It is ensured that at least one of the first emergency load and the second emergency load can work