The invention discloses a virtual terrain modeling method based on linear interpolation, and relates to the technical field of computer simulation. At present, virtual terrain generation can not be compatible with speed and accuracy. The technical scheme comprises the following steps that: 1) setting a threshold value T; 2) selecting a grid cell, and calculating the variance Var of an elevation value; 3) judging the threshold value T and the variance Var, if the threshold value is large, jumping to 4), and otherwise, jumping to 5); 4) adopting a bilinear polynomial to carry out interpolation calculation, and establishing the terrain structure of a current grid; 5) adopting a bicubic polynomial to carry out terrain interpolation calculation, and establishing the terrain structure of the current grid; and 6) calculating all cells, and finishing terrain modeling based on a regular grid. The technical scheme is compatible with speed and accuracy, the flatness of the grid terrain is judged,different interpolation models are selected, the bilinear polynomial interpolation is adopted in the grid with the flat terrain to guarantee modeling speed, and the simulation accuracy of an area with large terrain fluctuation is improved through the bicubic polynomial.