In this paper

three geometrical models

i.e.the stiffening ribs

the golden value and slabs slot-cut

were used to minimize the anticlastic distortion caused by cylindrical bent crystal to focus horizontal divergence

and to improve diffraction efficiency of the sagittal focusing monochromator.The parameters were optimized and the results were compared by numerical simulations with finite element analysis （FEA） and measurements of the classical crystal with long-trace-profiler （LTP）.Based on beamline parameters of the NSRL-XAFS

the golden value approach is an optimum solution for the second crystal of the monochromator.