Abstract: This paper introduced the design and manufacturing method of a phaseshifting transformer and its requirements for the quality of silicon steel, and put forward the method of making phaseshifting transformer core with the material of highgrade nonoriented silicon steel. The practice showed that the phaseshifting transformer made of highgrade nonoriented silicon steel can fully meet the national standards and user's requirements, which has little difference in performance with oriented silicon steel. And  most significantly, it has the advantage of greatly reducing material cost, reducing tranformer's noise and eventually improving the production efficiency, which has a wide application value.

Key words: high grade non oriented silicon steel, oriented silicon steel, phaseshifting transformer, iron core