The work aims to improve the hydrophobicity of herb residue fiber, compatibility of herb residue fiber/plastics and dispersity of herb residue fiber, so as to enhance the strength of herb residue fiber/plastics blends. With the herb residue fiber obtained by means of mechanical crushing and fermentation of herb residues of lucid ganoderma as the raw material, the herb residue fiber was pre-heated by heat treatment to improve the hydrophobicity of the fiber. The influence of heat treatment temperature and time on the mass loss rate, color difference, moisture and water absorption of herb residue fiber and the influence of heat treatment on physical and mechanical property of herb residue fiber/PP blends were researched. Compared with the untreated herb residue fiber, the moisture absorption of herb residues (temperature of 35 ℃ and relative humidity of 90%) subject to heat treatment at 180 ℃ for 40 min was reduced by 8%, and the water absorption was reduced by 30.6%. The melt flow rate, tensile strength, bending strength and impact strength of herb residue fiber/PP blends were increased by about 100%, 12%, 8.7% and 13%, respectively; and the homogeneity of the blends was also significantly improved. With the increase in the treatment temperature and the prolongation of the time, the moisture and water absorption of the herb residue fiber is remarkably reduced, but the change in mass loss rate and color difference is increased, and the influence of the treatment temperature is larger than that of the treatment time. The mechanical property, liquidity and homogeneity of the herb residue fiber and PP blends after heat treatment are significantly im-proved.