Abstract: By using frequency trellis diagram method to construct G function in DFH system, when bit number per hop increase or the number of available frequency choices decrease, SER will be degraded since the minimum free distance of frequency trellis diagram decrease. This paper proposes a G function constructing method based on status trellis diagram and corresponding encoding model. Theoretical analysis and simulation results show that the proposed methods solve the above problems effectively by keeping the length of code shift register and selecting the optimal tap structure.