Abstract: In radar products，waveguide assemblies are positioned and jointed through a series of holes on the end of waveguide flange．The positional deviation of the holes directly affects the consistency of different waveguide ports after the waveguide part is assembled．The higher the assembly accuracy of the waveguide part，the less the power loss of the radar transmission system and the better the electrical performance of the product．Therefore，it is very important to optimize the structure of the drill jig for waveguide flange and thus improving the drilling accuracy of the flange．