Abstract: In order to solve the problem of roof distributed photovoltaic in some thin plates and buildings with high requirements for cracks, this paper proposes to add a transfer beam under the photovoltaic support column and place the foundation pier on the primary and secondary beams. A two-dimensional simplified calculation method is proposed for the new layout. 3D finite element calculation was carried out for photovoltaic supports with and without a conversion beam by using 3D3S 3D software. By comparing the two-dimensional simplified calculation method with the three-dimensional finite element method, it can be seen that the calculation results of the two-dimensional simplified model are close to those of the three-dimensional model, which meets the engineering needs. At the same time, the simplified calculation method has the characteristics of simple calculation and practical. By comparing the three-dimensional finite element calculation of photovoltaic support with and without conversion beam, it can be seen that the use of conversion beam facilitates the arrangement of photovoltaic roof, but does not significantly increase the basic consumption.