The nonlinear behavior of surface waves on the interface between two uni-axis antiferromagnets is studied.The theoretical analysis and the numerical simulation show that there exist two thresholds:frequency threshold and power threshold.All the incident waves satisfying the two thresholds can steadily propagate in this new guiding structure.It is indicated that the peak field will jump from one antiferromagnet into another when the power increases. It is also revealed that the magnetic field amplitude on the interface is not power-dependent but frequency-dependent.