According to various embodiments, disclosed are a method by which a first server transmits a second message in a wireless communication system, and a device therefor. Disclosed are a method and a device therefor, wherein the method comprises the steps of: receiving a plurality of vulnerable road user (VRU) messages; transmitting a first message to a second server on the basis of VRU information obtained from the plurality of VRU messages; and transmitting, to VRU devices, a second message including second cluster information on the basis of the first message including first cluster information, wherein if VRU messages satisfying cluster conditions exist among the plurality of VRU messages, the first message includes the first cluster information for a cluster formed for the VRU messages, and the second cluster information includes information on a first cluster region for the cluster, and information on an expected time and a second cluster region associated with the expected time.