The utility model discloses a broken-down vehicle warning sign with a safe putting distance caution function. The broken-down vehicle warning sign comprises a bearer, a caution board and a safe putting distance caution device. The safe putting distance caution device, disposed between the bearer and the caution board, includes a distance measuring sensor, a master control single-chip microcomputer and an alarm. The alarm comprises a loudspeaker and a display screen. The broken-down vehicle warning sign helps to make up a defect of unintended safe operation of an owner of a broken-down vehicle, and warns the owner to put the warning sign within a safe distance scope through caution.