The invention discloses an insulation manufacturing method of a turbo-generator rotor lead. The insulation quality of the lead is improved through optimization of insulating materials and improvement on a binding technology and a curing technology; meanwhile, methods for setting the binding tension, the curing temperature, heating and cooling speeds, holding time and the like during insulation manufacturing of the lead are specified. According to the lead manufactured with the method, various materials can be free of air gaps and layering, a ventilating hole of the lead is not blocked, the insulation quality of the lead can be guaranteed, the lead can be insulated and reach the designed service life, and safe operation of a turbo-generator is guaranteed.