With the important role of UAV in the field of military and civil use, the performance index of UAV is required to be higher and higher. The application of PLC in UAV field brings new development direction to UAV. Based on this, this paper studies the application of PLC in UAV field. In the research, this paper uses different controllers to carry out many experiments on two UAVs, and makes a comparative analysis from the aspects of UAV flight control accuracy, flight out of control times, and debugging time. UAV A uses intelligent PID control for operation, and UAV B uses programmable logic controller for operation. The results show that in the first group of tests, UAV A is out of control for 3 times, the average debugging time is 10 minutes, UAV B is out of control for 1 time, and the debugging time is 7 minutes. In the second group of tests, UAV A is out of control twice, the average debugging time is 15 minutes, UAV B is out of control for 0 times, and in the third group of tests, UAV A is out of control for times is 2, the average debugging time is 12 minutes, the number of times of UAV B out of control is 0, and the debugging time is 0 min. In the fourth group of tests, UAV A lost control for 3 times, the average debugging time was 11 min, UAV B was out of control for 1 time, and the debugging time was 4 min. The experimental results show that the UAV with PLC has better flight performance.