Abstract: Spatial beam distribution of vacuum arc ion source in accelerating area was (determined) using a digital camera. Vacuum arc ion source was placed in a dynamic vacuum system, where the vacuity was better than 2×10~(-3) Pa. The integral image of vacuum arc ion source extraction beam in accelerating area was captured using a digital camera during ion source worked in pulse mode, and the relative luminance of extraction beam was educed subsequently through image processing, eventually, radial beam distribution of vacuum arc ion source in accelerating area was determined after Abel transform. The results show that spatial beam of vacuum arc ion source in accelerating area is approximately Gauss distribution, and the beam intensity close to ion source is 40 percent (bigger) than that near target.