The invention discloses a method for accelerating a ray-traced digital image rebuilding technology. The method is characterized in that the method combines the serial computation such as complex logic and affairs and the like caused by processing through a CPU with the problem of the high parallelism degree caused by processing through a Graphic Processor Unit (GPU). Aiming at two process steps of volume element electron density interpolating and ray tracing in the existing ray-traced digital image rebuilding technology, the method adopts the GPU parallelism process rather than the CPU sequential process. In the two process steps of the interpolating and ray tracing, each step has the characteristics of mass data, low relativity among data, same data executing procedure, high parallelism degree and high arithmetical computation density. With the GPU, the method can lead more computation units to be operated in parallel at the same time, thereby shortening the computation time, leading the rebuilding efficiency to be higher, and being capable of immediately rebuilding under a certain condition.