Abstract: In order to analyze the influence of high contrast grating(HCG) parameters and incident wavelength on beam deflection angle, the rigorous coupled wave method was used to design a deflectable non-periodic triangular HCG, and it is proved that 30.3° beam deflection can be achieved in the designed non-periodic triangular HCG by the finite-difference time-domain (FDTD). At the same time, it is found that when the refractive index of the low refractive index material increases from 1 to 1.4, the deflection angle of the transmission beam can achieve 11° tuning, and when the incident wavelength increases from 1.5μm to 1.6μm, the aperiodic triangular HCG can achieve 3.527° transmission beam deflection angle tuning. The results can provide theoretical guidance for the fabrication of high-performance beam deflection gratings in the future.