The invention provides a distribution network planning power off/on zero time difference data processing method and device. The method comprises the steps of carrying out de-duplication treatment on historical outage data to obtain the processed outage data; inputting the processed outage data into an initialized BP neural network to obtain an initial processing result, obtaining the difference value between the initial processing result and the expected result, adjusting the weight parameters in the BP neural network and repeating the processing steps if the difference value is outside the preset range, and obtaining the repeating times, terminating the processing process if the number of times is larger than a preset threshold or the difference value is within a preset range, and obtaining the processing result at the moment as a final data processing result. By means of the data processing method, a manager can pay the emphasis on the rule making and be released from complex data processing. A unified specification can be generated. Meanwhile, the running speed is increased, so that a desired result can be obtained only by processing tens of thousands pieces of data in a few minutes, and the accuracy is improved.