The topology of low-voltage distribution network is complex and unknown, and the power line communication(PLC) channel has interference and its status varies dynamically. So caused the unreliable and area limit of PLC. The necessity of automatic routing is explored through the analysis of the low voltage distribution network topology. On the basis of traditional ant colony algorithm, a hybrid routing combined ant colony algorithm, genetic algorithm and particle swarm algorithm is proposed. Simulation results show that the method can improve the convergence speed and guarantee the global optimal.