Since unmanned aerial vehicle’s（UAV’s） datalink is easily interfered by external electromagnetic radiation

it is necessary to improve the UAV’s active perception and threat alarm due to the high difficulty and bottleneck of the traditional anti-interference technology. In this paper

a design method on the environmental monitoring system suitable for the electromagnetic interference（EMI） adaptation of the UAV’s datalink is proposed. The determination of the key characteristic parameters of the monitoring system is studied. In addition

the structure of the system is designed. This system can monitor the characteristic parameters of the expected interfering frequency band by using the UAV’s antenna. The monitored frequency range of（fs1-50）～（fs10+50） MHz is determined. The sensitivity of the system is limited by the noise figure and the bandwidth of the resolution

but can be achieved by-96 dBm. Besides

the system can also use the telemetry datalink of the UAV to transmit and then display the EMI information at the location of UAV. However

the bandwidth affects the real-time performance of the feedback information. In the case of 1 MHz bandwidth

the single sweep period can reach 36 ms. After the simulation budget and the actual test

the effectiveness of the monitoring behavior for the system is verified. In the future

the research of UAV’s datalink adaptive to EMI will be further investigated.