For the remote communication scenario of UAV(unmanned aerial vehicle) at sea, the received power was measured on the basis of the wireless communication link between UAVs. In terms of large-scale path loss, the logarithmic distance linear model was used to fit the measurement data. The characteristics of remote air-to-air wireless channel at sea were analyzed, and the path loss index was obtained. The ray tracing method was used to simulate and verify the measurement results. Through the simulation of channel impulse response, the reasons for the rapid change of received power were analyzed in terms of multipath delay and power. The analysis results show that the multipath reflection in the nearshore causes the fluctuation of the received power and increases the path loss. Three kinds of distribution functions were used to fit the measured data, and the small-scale distribution characteristics of air-to-air wireless channel under sea surface and inshore communication conditions were analyzed. The analysis of the measurement results shows that the small scale characteristics are significantly affect by the land reflection, showing Gaussian distribution characteristics at the sea surface far from the land, but not typical distribution characteristics near the land.