Abstract:Aimed at instability of calculation formula for scattered wavefield in a medium with strong lateral velocity variation proposed by Huang's article "Expanded local Born Fourier migration method" the paper presented a new Born approximate calculation formula for scattered wavefield,applied the formula to recursive extrapolated processing of wavefield and then obtained a stable Born approximation pre-stack depth migration method.Comparing with Split-Step Fourier method and Phase-Screen method, the method achieved a good results in migration processing of shot gather data for Marmousi model.The approximation formula for scattered wavefield introduced in the paper can broaden the scope of using Born approximation.