A double proximity focusing X-ray image intensifier radiography imaging system was made as an experimental object.A new method was used for measuring and analyzing 3-D noise of this system.By analyzing 3-D noise of this system,the distribution of noise both in time field and frequent field with curves of three dimentions was drawn.The 3-D noise of a double proximity focusing X-ray image intensifier radiography imaging system was measured and analyzed under four different conditions with the help of digital image processing technology.The result of measurement and analysis agrees well with the performance of the two side proximity of X-ray image intensifier radiography imaging system.