Based on the transversely isotropic hypothesis, the ramie stalk and xylem were stretched, compressed, bent and twisted and the fiber layer was stretched and compressed to determine the basic mechanical parameters of ramie according to the requirements and standards of plastic tensile, compression and metal torsion tests and the bending performance test of sandwich structure. The results showed that the tensile elastic modulus of ramie stalk is 1 013.19 MPa, the compression modulus is 14.63 MPa, the shear modulus was 87.15 MPa, the poisson ratio of opposite surface is 0.38 and the poisson ratio of isotropic surface is less than 0.016 6. For the xylem, the tensile elastic modulus is 1 021.85 MPa, the compression modulus is 16.99 MPa, the shear modulus was 99.05 MPa, the poisson ratio of opposite surface is 0.33 and the poisson ratio of isotropic surface is less than 0.020 5. For the fiber layer, the tensile elastic modulus is 2 004.18 MPa, the compression modulus is 4.01 MPa, the shear modulus is 38.76 MPa, the poisson ratio of opposite surface is 0.58 and the poisson ratio of isotropic surface is less than 0.001 9.