Because of the complicated environment, various types of users, random time of power consumption and so on, the low-voltage power line communication has interference, which causes communication failure seriously. In this paper, the characteristics and laws of load and interference in low voltage power lines are studied. A channel noise model is established, and an intelligent active anti-interference technique for low voltage power line carrier communication is proposed. This technique matches the impedance of the transceiver controller with the impedance of the low voltage power communication line to a maximum, and broadens the spread spectrum technology. We further propose a method of actively selecting a high reliability band to communicate on the basis of spread spectrum, so as to overcome the strong attenuation and strong interference defects of low voltage power line. The experimental environment is set up, and the communication experiments are carried out for low voltage power lines, such as white noise, periodic noise and impulsive noise. The results show that the method is feasible.