With innovation cotton 958 cotton stalks as test material, shearing, compression and bending mechanical tests of cotton stalk in harvesting period were carried out in the universal test machine. The results showed that when the sample moisture content was in 30%~50%, the compressive intensity and shear intensity at the bottom and middle of cotton stalk was lesser, the intensity value were 1.66~3.13MPa and 0.74~1.12MPa, respectively. Cotton stalks bending intensity decreased with its moisture content increased. The bending intensity values of samples at the bottom was 4.20~5.08MPa. In the test of shearing, compression and bending, the consumption power of the sample was 2.98~4.32N·m, 2.91~4.34N·m, 1.51~4.18N·m, respectively.