Negative index material is one of wide research objects because of its unique characteristics, especially perfect imaging of photonic crystal slab. Silicon is a kind of the most widely applied materials in the integrated optical field because of its physical properties. In this paper, Si cylindrical rods are designed into hexagonal pattern in air to build a 2D photonic crystals flat. Band structure of this photonic crystals is calculated by the plane wave expansion method and the finite difference time domain method is used to simulate the effect on imaging when the surface structure of photonic crystals flat is changed. The simulation results show that photonic crystals slab can still image but image intensity will change by changing the both outermost radius or shifting outermost layer column laterally as photonic crystal slab equivalent refractive index is －1. And the position of image change and it changes accord with the classic Veselago relation of photonic crystal imaging as the surface structure of photonic crystals slab is changed in a certain range. But the phase difference of image and source will be 180° if the surface changes beyond this range and at the same time the image position will change sharply and the source and image will go against the Veselago relation. From the results it can be included that it can change the image intensity, position and phase effectively by changing the surface structure of photonic crystal slab.