Abstract: Provided are a transformer and a method for manufacturing a transformer. The transformer includes a magnetic core including: a top substrate and a bottom substrate arranged opposite to each other, and a plurality of winding posts located therebetween; and a winding including a primary side winding wrapped around the plurality of winding posts and a secondary side winding. The primary side winding includes two sub-windings connected in parallel, each including: a main turn including respective at least one turn wrapped on at least two winding posts, respectively, and the at least two winding posts have a single magnetic flux direction; and an additional turn including at least one turn wrapped on at least one additional winding post on which a corresponding main turn of the other sub-winding wraps, and the additional turn has a magnetic flux direction opposite to the single magnetic flux direction.