Objective:To construct a three－dimensional finite element(FE) model of non－constrained artificial disc (NAD) replacement and lumbar vertebrae L4~L5 segment as the standard digital model for further biomechanical research. Methods:The NAD FE model was designed by using Auto CAD and it was combined with lumbar segment FE model in aforementioned part one by Abaqus software. The L4~L5 model was validated by Force 1,a 400 N axial load which was made up of four 100 N stress force,then Force 2 which was composed of 400 N axial load and 10 N-m extension bending moment. Results:L4~L5 segment model was consisted of 33,976 nodes and 162,858 elements. Centrum was consisted of 161,679 tetrahedron elements. Endplate was consisted of 1,053 hexahedral elements. Ligament,articular capsule and fiber were consisted of 126 Link elements. The NAD model was consisted of 11,583 nodes and 44,927 elements. Endplate and nucleus pulposus was consisted of 1,053 and 3,724 hexahedral elements,respectively. The results of load test showed that the model of NAD and L4~L5 segment had good effect of visual and mathematics. Conclusion:Based on mimics software and CAD methods,the 3D FE model of lumbar motion segment and artificial disc can be constructed automatically with excellent simulation results. Mimics can provide precise model through calculation based on threshold and parameterization modeling. The implanted L4~L5 segment can be used for further biomechanical research of lumbar spine.