Disclosed are a method and an apparatus by which user equipment controls transmission power of a sidelink signal in a wireless communication system that supports a sidelink, according to various embodiments. Disclosed are a method and an apparatus by which user equipment controls transmission power of a sidelink signal in a wireless communication system that supports a sidelink, wherein the method comprises the steps of: calculating required power for each antenna unit included in a plurality of antenna units to which the sidelink signal is transmitted; determining reference transmission power on the basis of the required power calculated for the plurality of antenna units; and allocating transmission power for the plurality of antenna units on the basis of the reference transmission power.