Disclosed are, according to various embodiments, a method for transmitting, by a user equipment (UE), a first collective perception message (CPM) in a wireless communication system supporting a sidelink, and an apparatus therefor. Disclosed are the method and the apparatus therefor, the method comprising the steps of: obtaining first object information on surrounding objects through a sensor; receiving a second CPM including second object information; and transmitting the first CPM including the first object information and location information for the UE, wherein the second CPM further includes information on a location reliability of the second object information, the position information of the UE is corrected by applying an offset, based on the first object information and the second object information being object information for the same object, and the offset is determined by applying a ratio between a first position reliability related to the position information of the UE and the second position reliability included in the second CPM to a distance between an object position based on the first object information and an object position based on the second object information.