The invention provides a line loss calculation method based on a mobile client, and the method comprises the steps: enabling a mobile terminal of a line loss calculation platform to obtain data warehouse information from a data source and a target data table, allowing a user to define a data collection, conversion and loading process, and uploading the process to a substation; enabling the substation to transmit a business to a cloud side for execution; enabling the cloud side to carry out the data integration after the cloud side analyzes a task, extracting the data from the data source, carrying out the format conversion and reconstruction of the collected data, and adding the data to the target database. The method provided by the invention achieves the integration of a plurality of systems, effectively solves a problem of unified management in an enterprise, becomes a public data platform for an application system through obtaining the real-time data of all systems, and plays an important role in the future planning of a power grid. The method gives consideration to the difference between the measurement points and non-measurement points and the difference between different regions and the attribute difference, and enables the collection and calculation of real-time data to be more complete and precise.