The Ⅲ-Ⅴ nitride material such as InN GaN has many favorable physical properties including a wide direct band-gap(0.7-3.4eV),high absorption coefficients(105cm-1),and high radiation resistance.InGaN has been chosen as an excellent material for full-solar-spectrum photovoltaic applications utilizing its wide and tunable band-gap.But there is a high reflection of~18.4%as the sun light entering surface of InGaN/GaN heterojunction solar cell.So,anti-reflection films should be used to InGaN/GaN solar cell to decrease the reflection loss.The photonic crystal structure is a kind of anti-reflection film with no mismatched thermal expansion limitation which exists in the other anti-reflection films.In the paper,we reported our research work on the design and fabrication of photonic crystal structure of the surface of InGaN/GaN solar cell.FDTD Solutions is used to simulate the reflectivity of the surface of different hexagonal close-packed pillar structure with different parametes,period-a,diameter-d and height-h.When the parameters a is 500nm,d is 300nm,the reflectivity reached the lowest point 4.18%.The self-assembly method was used to fabricate the photonic crystal structure on the p-GaN surface,and the fabrication process was also researched.The photonic crystal structures on the surface of p-GaN were obtained and their characteristics of the antireflective film will be discussed in detail.