Abstract: In this paper, the structure of commonly used square lattice photonic crystal has been optimized. A new photonic crystal of embedded structure, which has been embedded in the gaps of square lattice with the same kind of square lattice, has been researched and designed. At the same time, this new structure photonic crystal is applied to F type micros trip antenna for improving its performance. A large number of simulation calculations are made through plane wave analysis method. Compared with the traditional microstrip antenna, the data shows that the return loss decreases from -18. 2465dB to -41. 0624dB, and the microstrip antenna has better impedance characteristics and radiation efficiency. The antenna pattern has also been improved, and back lobe radiation decreases about 5dB at most. The new structure microstrip antenna with photonic crystal reaches the aim to improve the performance of the antenna.