The invention discloses a user data missing estimation method for transformer area line loss calculation. The method comprises the steps of selecting a group of data adjacent to the vacant data in therepresentative day; comparing the group of data with all historical power utilization data which is in the same phase with the vacancy data and the user; finding a historical data value of which theuser power consumption behavior at the historical moment represented by the historical power consumption data is similar to the user power consumption behavior at the moment of the vacancy data, processing and recording the historical data at the moment corresponding to the vacancy position, and taking median values of all the recorded processed valuable historical data to estimate the vacancy data. The user data missing estimation method for transformer area line loss calculation provided by the invention can realize accurate estimation of power utilization data such as voltage or current representing daily missing through calculation and selection by only needing a small amount of sample data, has a high practical value, and is simple in process and easy to operate.