Provided are a method by which a terminal selectively performs an operation on the basis of a terminal operation mode in a wireless communication system, and a device for supporting the method. The terminal determines a terminal group to which the terminal belongs, on the basis of a battery residual quantity and a battery residual quantity threshold value, calculates channel quality on the basis of a downlink reference signal, determines a terminal operation mode on the basis of the determined terminal group, the calculated channel quality, and the channel quality threshold value, and performs an operation on the basis of the determined terminal operation mode, wherein the terminal group can be any one of an energy insufficient group (EIG) and an energy sufficient group (ESG).