A method for picking up a three-dimensional geometric primitive based on a GPU aims to overcome the defects that the picking-up efficiency in the prior art is low, the picking-up objects are limited, and the picking-up information amount is small. The method comprises the steps that rasterization is closed when picking-up drawing is conducted, mouse position information and a primitive vertex coordinate are changed to a standardized equipment coordinate system or a viewport coordinate system, target hitting judgment is conducted by judging the relation of a two-dimensional primitive after projection and a mouse position or a selecting frame in a geometry processor, and a picking-up result is returned to an application program by using change feedback. The method for picking up the three-dimensional geometric primitive based on the GPU is suitable for single body picking and also suitable for block picking, rasterization and fragment processing do not need to be conducted in the process of picking-up mapping, the picking-up process is efficient and quick, rich picking-up information can be obtained, the real-time interaction demand of graphics applications including a large number of geometric primitives can be met, and the method can be applied to various interaction type graphics applications, such as CAD systems, games, UIs and virtual reality applications.