The wireless sensor networks used in large-scale orchard must be able to run in various environments including different heights and densities of fruit trees. Moreover, as the radio channels have different propagation characteristics in different environments, it is important to study the propagation characteristics of wireless channel in orchards environments. This paper studied the propagation characteristics of wireless channel of 2.4GHz and 433MHz in orchard with different peach tree heights, respectively, and the channel fading and PLR (Packet Loss Rate) were tested. After that, the transmission range and PL (Path Loss) of wireless channel with different antenna heights were analyzed, and the communication channel fading model was also established. It can be observed that antenna height influence on the frequency of 433MHz is slightly larger, but the initial path loss of 2.4GHz wireless channel is greater. And it also can be found that the antenna height of 3.5 meters is better.