An amorphous alloy transformer iron core of a three-dimensional triangle structure belongs to the technical field of electrical devices. The amorphous alloy transformer iron core of the three-dimensional triangle structure is formed by piecing three identical rectangular single frames whose sections are approximately semicircular. A manufacturing method thereof comprises steps of cutting, winding, assembling, annealing and molding. The amorphous alloy transformer iron core of the three-dimensional triangle structure has the advantages of saving materials, reducing loss and noise, balancing three phases, enabling coils not to be sleeved, and being stable in performance and strong in anti-short circuit capacity.