The invention belongs to the technical field of winding wire manufacturing, and discloses an SZ-type internal insulation combined wire. The combined wire comprises conductors, an internal insulation material and an external wrapping insulation material, wherein the internal insulation material is arranged between the adjacent conductors, and two ends of the internal insulation material wrap the rounded corner parts of the adjacent conductors respectively. According to the invention, an S-shaped or Z-shaped insulation material is adopted for internal insulation to isolate the conductor, so thatthe inner insulation thickness of the combined wire is reduced while an inner insulation effect is achieved, the total thickness of the combined wire is reduced, and the space of a transformer is reduced while the insulation material is saved; and the combined wire is processed by adopting an SZ-type internal insulation mode, so that the production and processing difficulty can be reduced, and the operation efficiency is improved.