The invention discloses a warming method suitable for a high-pressure and medium-pressure combined starting steam turbine generator unit. On the basis of an original rotating speed control system of the unit, a set of automatic warming logics is added, through real-time correction of a high-pressure main steam valve position function g (deltax) and a medium-pressure regulating valve position function h (deltax) in a DEH control system of the steam turbine generator unit, whole-course automatic warming of the high-pressure cylinder and medium-pressure cylinder combined starting unit is achieved, the problems of long warming time and incomplete warming existing in existing steam turbine generator units adopting high-pressure and medium-pressure combined starting are solved, meanwhile, the safety risk of existing parameter-reduction starting warming technologies to the operation of existing units can be avoided while energy saving and emission reduction are achieved, and the current defects in the prior art can be overcome.