According to the order difference between the Hilbert transform and the partial derivative, reconstruction algorithms for cone-beam projections along the circular super-short-scan trajectory can be categorized into two classes, named FPD and BPD algorithms. They are theoretically equivalent. However compared with the former,the later has smaller reconstruction range. Based on the decomposition of 3D Radon inversion transform,this paper derives a new reconstruction formula which belongs the BPD algorithms. Unlike the original method,an approximate reconstruction result as the FPD method is obtained by introducing the partial derivate with respect to the variable of cone direction. In addition,the Radon data which are not offered in the circular trajectory are compensated by the correction factor of rotation angle. The simulation experiment shows that the proposed algorithms effidently avoid the problem in the BPD algorithms and obtained better reconstruction results.