An 1800-kilovolt and 4500-kilovolt-ampere power frequency non-partial discharge test transformer is mainly used for providing a non-partial discharge power frequency test power source for testing and studying of extra-high voltage power transmission and transformation equipment, and comprises an insulating cylinder. A hollow-square-shaped iron core is arranged in the insulating cylinder, and is twined by a coil. Chamfers are arranged on right angle corners on the outside of the hollow-square-shaped iron core. The coil is in a trapezoid shape. The iron core outside the coil is connected with two iron core shielding cases which are respectively arranged on the left side and the right side of the iron core. An oil protective screen is arranged outside the coil in a sleeved mode. Due to the design, the insulating distance of the coil to the outside is prominently reduced, magnitude of partial discharge is reduced, and the magnitude of partial discharge of the equipment is lower than or equal to 5 p C. The 1800-kilovolt and 4500-kilovolt-ampere power frequency non-partial discharge test transformer can meet requirements of a power frequency tolerance test and partial measurement under power frequency voltage of the extra-high voltage power transmission and transformation equipment (mainly referring to an extra-high voltage gas insulated switchgear (GIS)), and at the same time can meet the requirements of controlling, connector measuring and insulation level of a switch union test (power frequency plus power frequency, shock plus power frequency).