High frequency (HF) propagation can achieve long distance, low cost communications and it is one of the most important communication methods. The focus of this research is to develop an appropriate mathematical model for HF radio waves to communicate efficiently over various surface of the earth. First of all, the multi-hop attenuation (MHA) model is established which takes free space loss, ionosphere loss and surface reflection loss into account. [1] The effect of the free space loss and the ionosphere loss is simplified, and subsequently the relationship between signal attenuation and frequency variation under different wind speed is revealed. At the same time, the contrast of signal attenuation off a calm ocean and a turbulent one is conducted. [2].