An unmanned aerial vehicle system comprising: a vehicle; a housing mounted on the vehicle and having an inner space; a launching unit located inside the inner space; an unmanned aerial vehicle accommodated in the inner space and configured to be launched from the housing, the unmanned aerial vehicle comprising wing units configured to guide flight of the unmanned aerial vehicle after launch and an output unit configured to output information; and a controller configured to: receive information of a driving state related to the vehicle from the vehicle; control the unmanned aerial vehicle to launch from the housing when the driving state of the vehicle meets a preset condition; control the wing units to maneuver the unmanned aerial vehicle to a position after launch that is set based on first information related to the driving state; and control the output unit at the set position to output warning information related to the driving state corresponding to brief information related to an accident to be notified to other drivers, simple warning information to induce careful driving, information including a guide for another path to another vehicle, wherein the set position corresponds to a rear area spaced apart from the vehicle, and wherein the preset condition includes at least one of a collision with an external object, a sudden stop and a sudden change of driving state of the vehicle due to an external force. a vehicle; a housing mounted on the vehicle and having an inner space; a launching unit located inside the inner space; an unmanned aerial vehicle accommodated in the inner space and configured to be launched from the housing, the unmanned aerial vehicle comprising wing units configured to guide flight of the unmanned aerial vehicle after launch and an output unit configured to output information; and a controller configured to: receive information of a driving state related to the vehicle from the vehicle; control the unmanned aerial vehicle to launch from the housing when the driving state of the vehicle meets a preset condition; control the wing units to maneuver the unmanned aerial vehicle to a position after launch that is set based on first information related to the driving state; and control the output unit at the set position to output warning information related to the driving state corresponding to brief information related to an accident to be notified to other drivers, simple warning information to induce careful driving, information including a guide for another path to another vehicle, wherein the set position corresponds to a rear area spaced apart from the vehicle, and wherein the preset condition includes at least one of a collision with an external object, a sudden stop and a sudden change of driving state of the vehicle due to an external force. receive information of a driving state related to the vehicle from the vehicle; control the unmanned aerial vehicle to launch from the housing when the driving state of the vehicle meets a preset condition; control the wing units to maneuver the unmanned aerial vehicle to a position after launch that is set based on first information related to the driving state; and control the output unit at the set position to output warning information related to the driving state corresponding to brief information related to an accident to be notified to other drivers, simple warning information to induce careful driving, information including a guide for another path to another vehicle, wherein the set position corresponds to a rear area spaced apart from the vehicle, and wherein the preset condition includes at least one of a collision with an external object, a sudden stop and a sudden change of driving state of the vehicle due to an external force.