A transformation structure for a redundant power system which includes at least two power supplies and a first circuit board to cluster the power supplies and deliver output thereof and a second circuit board electrically connected to the first circuit board. The second circuit board is coupled with at least one transformation module according to output potentials defined by users. The transformation module receives power from the second circuit board and regulates at least one output power. Hence, the present invention could be formed in an independent module with a function of power transformation. Thereby, the transformation module can be selected and mounted onto the second circuit board according to customer's requirements. The second circuit board has a sufficient area serving heat radiation and insulation. The present invention can obtains merits of decreasing the product size, enhancing heat radiation and providing changeable output specifications to meet customizing requirements.