In the present work, hydrothermal-microwave treatment was used for juvenile and mature ash wood softened treatment. Ratio of longitudinal compressing, single and muti-dimensional minimal curvature radius were used to evaluate the softening effect. XRD and FTIR were used for describing surface composition and crystallinity, analyzing the effect of softening treatment on longitudinal compressing and bending ash wood. The results show hydrothermal-microwave treatment can soften ash wood significantly. With the hot water extract moved, lignin and hemicellulose decreased, in addition, the number of hydroxyl groups on wood surface increased significantly. For the non-crystalline region, microfibre tended to arrange orderly and the degree of crystallinity increased. In the crystal region, the hydroxyl of the sur-microfibre was exposed and the hydrogen bonding enhanced and the width of crystal region increased. When treated under the optimum condition of scheme B, the ratio of longitudinal compressing reached maximum, and the single and muti-dimensional radius reached minimum.