The invention relates to the field of electronic techniques, in particular to a single chip microcomputer program upgrading method and device. According to the single chip microcomputer program upgrading method, a read-only storage area is set in a user program code area of a single chip microcomputer and used for storing a default program of the single chip microcomputer; firstly, partitioned user programs in the single chip microcomputer are verified, when verification of all the partitioned user programs fails, the default program of the single chip microcomputer is operated, the single chip microcomputer returns to a default mode, user programs in a read-write storage area are restored, and the single chip microcomputer returns to the initial state before upgrading. After the user programs are restored, the single chip microcomputer can continue to be upgraded, and safety and reliability of a whole distribution type system are improved. Moreover, when verification of the user programs succeeds and upgrading of the user programs of the single chip microcomputer is allowed, user programs corresponding to target version numbers which are issued by an upper computer in a broadcasting mode are received, multi-node simultaneous upgrading is achieved, and upgrading efficiency is improved.