In order to solve the problem of air-to-ground communication distance due to the limitation of transmitted power and antenna size in Unmanned Aerial Vehicle (UAV) swarm data link system, a method of distributed coordinated coherent communication system is proposed. Based on the adjusting and compensation of channel feedback, the UAV swarm nodes can transmit the communication signal simultaneously, and then the coherent received signal can be obtained in the ground node. A prototype system is built in the laboratory. Comparison of the theoretical analysis and measured data, the capacity of multi-node coordinated coherent transmission is verified. Experimental results show that the power gain is increased 10.58 dB when 4 nodes are coordinated. The proposed method makes it possible to expand communication distance and improve anti-jamming ability while the UAV swarm data link terminal and omnidirectional antenna remain unchanged.