Objective To fabricate a foldable microplate for single cell culture and establish finite element model of the folding microplate, so as to calculate traction force of single cells during contraction in three-dimensional (3D) state.Methods The folding angle of the microplate casued by cell traction force was calculated. Then the relation between bending moment and folding angle as well as the relation between traction force and bending moment were derived by using finite element simulation, so as to realize the characterization of traction force for singel cell in 3D state.Results The folding angles of the microplate with HSF and MC3T3-E1 cells in 3D state were 73°-173° and 49°-138°, respectively. The single cell traction forces of HSF and MC3T3-E1 cells were 55-210 nN and 52-161 nN, respectively.Conclusions The proposed method for measuring traction force of single cells in 3D state by fabricating the foldable microplate for single cell culture will provide some references for further development of calculating traction forces in 3D cell adhesion, spreading and migration.