A new method for multiple aircraft collision avoidance using cost map construction is proposed. The objective of this work is to find a solution to the problem of conflict resolution for multiple ADS-B equipped aircraft. Development of satellite-based navigation technology enables air traffic controller (ATC) and pilot to monitor multiple aircraft in relative long range to the currently used TCAS II system which resolve in last minute. A new conflict resolution scheme is thus developed to avoid collision longer before it happens. In this scheme, a risk map is defined to describe the risk of collision. Based on this map, a cost-minimized trajectory can be found for a single aircraft, using the Dijkstra's algorithm. For the multiple aircraft trajectory planning, the index method is implemented to reduce the computational complexity. Finally, comparison with existing method and several major conclusions are drawn based on the proposed study.