Subsurface structure imaging method for undulating surface

The invention provides a subsurface structure imaging method for undulating surface. The method comprises the steps that S1 observation data inputting and velocity field offsetting are carried out, and at the same time the initial value of a reflection coefficient model is pre-set; S2 observation data are sampled or re-sampled based on correlation coefficients to acquire offset data; S3 data residual are acquired according to the current reflection coefficient model and the offset data; and S4 the gradient is determined according to the data residual, and reflection coefficient model iteration is carried out based on the gradient to acquire the final reflection coefficient model. According to the invention, the method introduces a sampling policy based on the correlation coefficients, which avoids random sampling; the amount of the offset data is reduced, and at the same time the offset data are effectively prevented from greatly changing with the number of times of iteration; the destruction, which is caused by the change of the offset data, of the gradient direction conjugacy and the jitter of a convergence curve are weakened; and the iteration computational efficiency and the final imaging quality are improved.