One dimensional photonic crystals with insertion of defect are applied to the microstrip antenna. The photonic crystal microstrip antenna is designed at 0.2 THz frequency,and the three dimensional electromagnetic simulation software HFSS based on finite element method and software Origin are used to simulate and draw. The study results show that the gain of the photonic crystal microstrip antenna can reach 9.3 dB,which is increased by 2.5 dB compared with the gain of normal microstrip antenna. The effect of different cycles of photonic crystal on the proposed microstrip antenna is discussed. When the cycle is three,the return loss of the antenna is lowest. Taking the three cycle of photonic crystal microstrip antenna as an example,the influence of the different distances between the photonic and the microstrip antenna on the gain and the return loss of the proposed antenna is discussed.