The invention discloses an RS485 electric meter power failure alarm reporting method based on a timing broadcast strategy, and relates to a power failure alarm reporting method. At present, an RS485 mode is a simplex and duplex mode, so that an intelligent meter cannot initiate event reporting actively, and a large number of meter power failure event are missed and reported belatedly. The method comprises the following steps: 1) carrying out timing polling, wherein the II-type concentrator broadcasts and sends a 'power failure state inquiry' message at regular time; the II-type concentrator isoperated in a meter reading gap period, and starts to initiate timing rotation training when the meter reading is finished on that day or when more than one time period is exceeded; 2) carrying out bus monitoring; 3) reporting a single-meter power failure event; and 4) reporting an RS485 conflict processing event. According to the technical scheme, a specific timing broadcast strategy of the II-type concentrator is adopted, the super capacitor is used, the gap period and the calling characteristic after meter reading of the II-type concentrator are effectively utilized to the maximum extent,the problem of active reporting of the RS485 intelligent meter is solved, and the accuracy and the real-time performance of a power failure event of the RS485 intelligent meter are greatly improved.