Femtosecond laser processing has litle-thermal effects,high precision,and is not particular about materials.Aiming at the machining requirement for nozzle′s spray holes,as a key part of the high pressure common rail injection system for diesel engine,a femtosecond laser processing apparatus with three-wedge scanning system was designed for technical research of taper holes′machining.Then tests of the taper holes′physical dimensions and the flow rate of the fuel jet nozzles were carried out with three coordi...