Ultra-fast dynamic process can be recorded by ultra-short pulsed digital holography with angular multiplexing technique, in which the angle between reference beam and object beam has to be restricted to within a few degrees due to the restricted pixel size of CCD in the recording. In this report, spatially angular multiplexing technique is introduced, and the its applicability has been proved through a simulation experiment of digital holography with CW laser. Besides, optical set-up based on this technique is designed. Computation result shows that a series of dynamic multi-images in nanosecond time scale of ultra-fast process can be automatically recorded on a piece of digital hologram.