The invention relates to a power distribution automation protection constant value online evaluation method. The method comprises the following steps: S1, initiating a protection constant value notification sheet flow from a PMS system; s2, transferring to a GOMS system, and automatically synchronizing to a production control large-area DMS system through a wide-area transmission service via a management information large area and forward and reverse isolation equipment; s3, downloading the protection constant value notice passing downloading audit to a protection terminal on the operation line through the forward and reverse isolation equipment via the safety access area; s4, the DMS system service automatically and regularly calls and measures protection constant values in all downloadedand online operated protection terminals in the jurisdiction, automatically compares the protection constant value notice constant value with a constant value returned by the call and measurement terminal, and judges whether the terminal protection constant value is correctly downloaded according to a standard or not; s5, automatically analyzing the action condition of the terminal along the line; and S6, the DMS transmits the analyzed data to a large four-area management information large-area WEB system through forward isolation equipment, and displays an analysis result.