Abstract: We propose the synchronal boundary process theme and depth error correction theme while wave-field initialization for pre-stack depth migration from irregular surface directly. The former is used to eliminate the image in non-wave field area and the latter is used to clear up the affection to the image of subsurface structures caused by the depth error while sampling the surface. These two themes optimize the regular one-way wave-equation based pre-stack depth migration methods from irregular surface, and make better results for the structure imaging under complex conditions. We present these two themes using FFD operator on the SEG irregular surface model dataset. The results demonstrate the improvement of the precision of the pre-stack depth migration from irregular surface. The presented method is also effective for any wave equation depth migration method from irregular surface based on depth propagator in frequency domain.