The invention discloses a method and a system for distributing quantum keys to terminals in a transformer area, the transformer area comprises a plurality of blocks, and the method comprises the following steps: determining the optimal quantum key distribution quantity of each block; sending a plurality of root keys to each terminal in the block, wherein the number of the root keys is equal to theoptimal quantum key distribution number of the block to which the terminal belongs; and enabling each terminal to calculate the received root key according to a preset algorithm to obtain a respective terminal key, wherein the terminal keys are different. According to the method and the system for carrying out quantum key distribution on the terminals in the transformer area provided by the embodiment of the invention, the secure encryption transmission of the power distribution and utilization service data can be realized, the effective utilization of the quantum keys is realized, the security is improved, and the demand of a large number of keys required by the power distribution and utilization terminal can be met.