The invention discloses a power management system applied to a fault indicator of a power transmission line and a design method of the power management system. The power management system comprises anenergy taking coil, an induction power taking module, a supercapacitor energy storage module, a dry battery module and a fault indicator power system, wherein the energy taking coil is arranged on ahigh-voltage power transmission line and is connected with a voltage input interface of the induction power taking module, a DC stable voltage output interface of the induction power taking module isconnected with a DC voltage input interface of the supercapacitor energy storage module, a capacitance-voltage output interface of the supercapacitor energy storage module and a voltage output interface of the dry battery module form in a parallel mode and then are connected with a voltage input interface of the fault indicator power system, and a voltage output interface of the fault indicator power system is connected with each functional module of the fault indicator system. The power management transmission line has the characteristics of low carbonization, lightness, compactness, high environmental applicability and the like and is convenient to install and is applicable to an occasion for monitoring a running state of the power transmission line in real time.