This article analysises designes for several filters using in the approximate three-dimensional cone beam reconstruction principle, and analysises the effect of CT’s image quality. CT is an advanced imaging technology, and have been used in many fields. The current CT image reconstruction alrorithms mostly use filtered back projection method.Filtering is the core of this method. This article analysises and designes for several filters using in the approximate three-dimensional cone beam reconstruction principle. It analysises the different filter functions affecting the quality of CT image reconstruction according to the results of the projection data’s image reconstruction. These filters can be better to meet the requirements of the actual image reconstruction.