The utility model discloses a yoke-broken iron core of a three-phase amorphous alloy transformer. The yoke-broken iron core comprises three unit iron cores with upper unit iron yokes capable of being opened. Each unit iron core is formed by sequentially nesting a plurality of single iron cores. The cross section of each single iron core is in the shape of a special-shaped trapezoid with an upper bottom, a lower bottom, a straight line waist and an arc line waist, and the cross sections of unit iron core pillars and the cross sections of the unit iron yokes are basically in a semicircular shape. According to the yoke-broken iron core of the three-phase amorphous alloy transformer, the three iron core pillars of the yoke-broken iron core are respectively formed by connecting the diameter part of the cross section of the left unit iron core pillar of one unit iron core and the diameter part of the cross section of the right unit iron core pillar of another unit iron core in a butt mode, the cross sections of the three iron core pillars are basically in a circular shape, and the circle centers of the cross sections of the three iron core pillars compose an equilateral triangle. The yoke-broken iron core of the three-phase amorphous alloy transformer has the advantages of being good in performance, low in noise, capable of saving materials and low in cost. More importantly, a coil of the transformer can be wound independently, and installing the coil of the transformer in a sleeved mode is greatly facilitated.