To study the hydrodynamic instability in laser fusion implosion, X-ray diagnostic technology with large field of view and high resolution is needed. Fresnel zone plate (FZP) is a kind of circular aperiodic grating structure, which can realize high spatial resolution imaging of X-ray. In this paper, the simulation research of high-resolution X-ray diagnosis technology based on diffraction imaging is carried out, showing the application prospects of FZP for hydrodynamic instability research. Based on the diffraction theory, the theoretical model of FZP is established, and the structural parameters of FZP with working energy point of 8.04 keV are designed according to the diagnostic experimental environment. Based on the optical simulation model, the color difference of FZP imaging is simulated, and the relationship between spatial resolution and spectral bandwidth is given. The simulation results show that the bandwidth of light source is less than 0.2 keV, and the resolution of FZP is better than 3 μm. The simulation of grid backlight imaging shows that FZP can achieve good resolution (less than 3 μm) within 0.8 mm field of view.