A method for managing power of a wireless terminal in a wireless local area network (WLAN) system according to one embodiment includes: transmitting, by a first wireless terminal that switches between an awake state and a doze state based on a power save mode for power management, a target wake time (TWT) request frame for requesting first target beacon transmission time (TBTT) information, which indicates a reception time of a first beacon frame, and listen interval information, which indicates a reception interval for a subsequent beacon frame, to a second wireless terminal; receiving, by the first wireless terminal, a TWT response frame including the first TBTT information and the listen interval information from the second wireless terminal in response to the TWT request frame; switching, by the first wireless terminal, to the doze state after receiving the TWT response frame; switching, by the first wireless terminal, to the awake state according to the first TBTT information in order to receive the first beacon frame; and switching, by the first wireless terminal, to the doze state after receiving the first beacon frame.