The invention belongs to the field of electric power automation, and relates to monitoring of power quality. The invention discloses a smart preservation technology for power quality data. According to the invention, a method includes: first acquiring data from a power quality monitoring apparatus, storing the data acquired in a distributive server cluster which is based on cloud computing, and conducting redundant backup of the data; reading the data in the distributive server cluster database, and first assessing the completeness of the data. If the incompleteness of the data is determined, then data is called up from the database server; and if the calling up fails, the data will be called up from the power quality monitoring apparatus; and if the calling continues to fail, then the data is determined to be lost permanently and the data lost is recorded and the data preservation technology is applied to the recovering of the data; finally, complete data are employed in the statistic analysis of the power quality.