The invention discloses a low voltage three-phase load balancing control method based on the on-load commutation technology. According to the method, each outgoing topology structure at a low voltage side of a distribution transformer on an outgoing wire is taken as a model, a control load capacity and a switch position of a commutation switch on the outgoing wire are acquired, a three-phase load unbalancing degree is detected and calculated in real time, if the three-phase load unbalancing degree surpasses a given value, an adjustment-needing load is calculated through a mean value iterative method, a motion-needing commutation switch number and a commutation switch adjustment phase sequence are acquired through utilizing the multi-target optimization principle, and three-phase load balancing is realized. According to the method, factors such as the switch motion frequency and the three-phase load unbalancing degree are fully considered, when the three-phase load unbalancing degree is guaranteed to reach a standard value scope, the smallest switch motion frequency and the lowest commutation cost are realized, moreover, uninterrupted user power supply requirements are realized during load transfer, namely the on-load commutation technology.