A manufacturing method of an insulation structure of a 3 megawatt wind driven generator stator coil comprises the following steps: 1) half-lapped wrapping a corona-resistant polyimide film strip on a copper flat wire; 2) half-lapped wrapping a layer of single-side backed dry mica tape; 3) half-lapped wrapping a layer of corona-resistant polyimide film strip; 4) half-lapped wrapping a layer of single-side backed dry mica tape; 5) half-lapped wrapping a layer of corona-resistant polyimide film strip; 6) half-lapped wrapping a layer of polytetrafluoethylene strip; and 7) flat-wrapping a layer ofalkali-free glass fiber strip. According to the insulation structure, the insulation thickness is thin, turn-to-turn insulation thickness is decreased from 0.40mm to 0.21mm, the thickness of insulation to ground is decreased from 1.84mm to 1.70mm, and the temperature class of insulation is increased from F level to 200 level, thus realizing a smaller and lighter insulation structure and increasing the power of the insulation structure having the same volume and weight as a motor. The price of the corona-resistant polyimide film strip is only one third of that of an imported corona-resistant polyimide film strip. The method can be widely applied to the stator coils of 3 megawatt double-fed and direct-drive wind driven generators, petroleum drilling electric machines and the stator coils ofoil extraction electric machines, main-line locomotives and main train unit traction motors.