The 35kV series oil-immersed power transformers are designed with advanced technology, featuring significant improvements and enhancements in materials, structure, and processes. High and low voltage clamps are secured using steel tension bands or upper and side beams, forming a robust frame structure that enhances core clamping force and shock resistance during transportation. They possess strong short-circuit resistance, an aesthetically pleasing appearance, reliable operation, low losses, and minimal noise, reaching the advanced level of similar products internationally. Our SZ11-8000/35 transformer prototype successfully passed the sudden short-circuit test conducted by the national transformer testing center. The longitudinal oil channels in the high and low voltage windings facilitate heat dissipation, significantly reducing copper oil temperature differences and internal winding hot spots.