The invention discloses an elastic wave forward
simulation technology based on the space-time dual-variable grid, comprising the following steps: determining the
stability conditions of the target area and the background area according to the speed parameter and the elasticity parameter of the underground medium aiming to the known earthquake geological model so as to calculate the size of the space grids with different dimensions and perform the
discretization process to the speed field; obtaining the space arbitrary precision difference formula of the grid point variables with different dimensions by using the Taylor's formula and the finite difference technology, which is the arbitrary even order accuracy space difference formula of the space constant
grid operator and the space variable
grid operator, and calculating the
wave field values of the precise division area, the rough division area and the middle transitional belt area by using the deduced space difference formula; in the
wave field extrapolation process of the time layer, using different time sampling intervals to different grid division areas and meet the partial stability condition, obtaining the
wave field value of the precise grid point in the precise time layer and the wave field value of the rough grid point in the
global time layer; in each
global time layer, transmitting the wave field value of the precise grid division area to the rough grid division area, thereby obtaining the space wave field value of the whole speed field at the said moment; performing the wave field extrapolation on each time layer by the said method and obtaining the forward
simulation record of single cannon. The partial stability condition of the shallow layer can be met, so as to avoid the
frequency dispersion noise.