The invention relates to a method for manufacturing 1250 MW nuclear power half-speed turbogenerator stator through-core screw rods. According to the method, technical innovation is made on the insulation manufacture of stator through-core screw rods to break through the conventional insulation winding and curing technology, the entire insulation part is wound into an integer by combining mechanical winding and manual winding of resin-rich mica tapes and then using heat shrinkage tapes, and then is formed by heat curing shrinkage. The 1250 MW nuclear power half-speed turbogenerator stator through-core screw rods manufactured according to the method not only have high mechanical properties and electric properties but also the insulation level of the through-core screw rods reaches F level, so that the application of high pressure by the stator through-core screw rods to stator plates is guaranteed without motor operational accidents caused by burning of the iron core due to the short circuit of the iron core which is caused by the insulation damage of the screw rods, and with the method, safe and reliable operation of 1250 MW nuclear power half-speed turbogenerators is guaranteed.