Wang, H.Y. Luo, P. Ma, Y.X. Shi, H. Yang, J.L. JACoW Publishing Geneva, Switzerland The under-construction High Energy Photon Source is a fourth-generation synchrotron radiation source. It has two operation modes for its BF beamline station’s insertion devices and extremely high thermal loads. Therefore, it is necessary to use filters to modulate the energy and power of the beam. Filters can effectively absorb part of the thermal load in synchrotron radiation, thereby reducing the thermal load at downstream optical components or experimental samples. This article introduces the parameter design method of the absorbers in the filter, including material selection, thickness allocation, combination method of absorbers, and determination of the number of filter groups. A complete design process is obtained, and key factors affecting the use of filters are analyzed, providing a theoretical basis for the optimization design of the filter equipment. The filter designed using this method has been successfully applied to BF beamline of HEPS.