The invention discloses a method and a system for power-fail protection of communication equipments, and a power controller. The method is applied to a system comprising a power controller, a power detection unit, and an energy storage conversion unit. The method includes: a power controller acquires the information of one or more circuit boards requiring protection in an equipment; when the power controller determines the equipment is currently in power-fail status, the power controller indicates to gate the switches between an energy storage conversion unit and one or more circuit boards, and provides the pre-stored electric energy to the one or more circuit boards. According to the technical solution provided by the present invention, the problems in the related art that the power consumption is large, the cost is high and it is difficult to implement when the power-fail protection is performed for all circuit boards of a frame are solved, so the power consumption is effectively reduced and the cost is saved.