A collision avoidance apparatus for a vehicle includes a data collection module, collecting first automatic dependent surveillance broadcast (ADS-B) data of the vehicle itself, second ADS-B data of at least other one vehicle and a detection result related to a radar reflection wave reflected from an object within a first range; and a possible collision determination/avoidance module, electrically connected to the data collection module, determining whether the other one vehicle will collide with the vehicle according to the first and second ADS-B data and whether the object will collide with the vehicle according to the detection result, so as to generate a determination result, wherein the signal processing module generate a control signal to control the vehicle perform a corresponding action according to the determination result. Thus, collision avoidance can be achieved.