The invention discloses a cyanide-free brush electroplating solution based on an EDTA multi-element coordination system and a preparation method thereof. The solution at least comprises soluble silversalt and an EDTA multi-element coordination system, the EDTA multi-element coordination system comprises a main coordination agent and an auxiliary coordination agent, the main coordination agent isEDTA, and the auxiliary coordination agent is 5, 5-dimethyl hydantoin and potassium pyrophosphate. The electric brush silver plating solution is stable, the quality of formed plated silver is good, the performance of a silvered layer meets the requirement of the standard for the silvered layer of the contact finger of the high-voltage isolation switch, and clean, efficient and safe cyanide-free electric silver brush plating technology repairing can be achieved.