The invention discloses a system for evaluating health condition of a distribution transformer, and relates to the technical field of power. The system can carry out the evaluation of the health condition of the distribution transformer according to the actual condition of a power distribution network and the related technical requirements. The system comprises a data collection module which is used for achieving the online collection and offline collection of data, and is also used for synchronizing the collected data with an external system; a data management module which is used for storing the data collected by the data collection module; a knowledge base module which is used for storing a sample library, wherein the sample library is used for storing the threshold values of all state quantities of the distribution transformer; and an evaluation module which is used for carrying out the call of the data stored in the data management module, comparing the data with the threshold values of the state quantities of the distribution transformer in the sample library, and carrying out the single diagnosis of the distribution transformer; or is used for carrying out the integrated diagnosis of the distribution transformer through the data from the data management module.