A virtual grid imaging method capable of eliminating scattered radiation effect and an imaging system thereof for imaging with high energy rays, in which scattered rays reaching a surface of a detector are not filtered, and data of the scattered rays and straight rays are all sampled. The method includes decomposing a digital image into multi-band images from high to low according to frequencies; performing de-scattering process for low-frequency band images; performing contrast enhancement process for high-frequency band images; and merging the images of various frequency bands processed in the second and third steps, and forming an output image. In digital X-ray imaging the scattered radiation effect is eliminated. Significant reduction of the dosage of the rays, in which only one third of the required dosage of a common grid is used to obtain the same image brightness.