The utility model discloses a monitoring system for transmission line, the regional edge of transmission line that covers at former signal sets up the wireless router who is connected with wireless network card, and at former no signal or the relatively poor transmission line regional setting wireless network bridge of signal, the radio signal that wireless network bridge reinforcing wireless router sent, make the signal cover completely at transmission line, realize the place that the mountain area equisignal is on the weak side or the no signal covers, the regular transmission of supervisorysignal, and then reach the mesh of the transmission line's in the place that the on the weak side or no signal of signal covered intelligent monitoring.