The invention discloses a voltage monitoring method based on big data processing and relates to the technical field of electrical variable monitoring methods. The method comprises the following steps of carrying out distributed storage, calculation and processing of voltage data through a Hadoop distributed cloud computing platform; analyzing the voltage data after distributed storage, calculation and processing through data mining, and finding out laws from a large amount of data; and predicting corresponding indexes of the voltage data by statistically analyzing the data whose laws are found. The method can manage the massive voltage data uniformly. Based on the big data mining technology, the reason for the voltage abnormity can be excavated, which can support the construction and maintenance of the smart power grid.