The invention relates to a low-voltage distribution network three-phase unbalanced treatment system and method controlled by a phase-change switch cluster. The system has the following technical characteristics: the system comprises a current transformer, a main control terminal, main control switches and intelligent phase-change switches; the current transformer is installed on the low voltage side of a transformer and connected to a three-phase power grid, and is used to measure a current signal of the low voltage side of the transformer and a beginning end of a three-phase branch line; themain control terminal is used to monitor the unbalance degree of a three-phase line on the low-voltage side of the distribution transformer, collect three-phase current data at the beginning ends of three-phase branch lines in real time and issue a phase-change instruction to the intelligent phase-change switches; the main control switches are connected with the intelligent phase-change switches,and is used to monitor the unbalance degree of the beginning ends of the three-phase branch lines and perform phase-change control on the intelligent phase-change switches; and the intelligent phase-change switches are connected with loads, and are used to receive the phase-change instructions of the main control terminal or the main control switches to switch phases. The imbalance degree of the low-voltage side of the distribution transformer and the beginning ends of the three-phase branch lines can be effectively reduced.