Abstract: 【Objective】In order to solve the resources waste and secondary pollution caused by burning wasted reeds in lakes and wetlands, reed material was treated by means of steam explosion to explore the feasibility of utilizing it as a raw material for reed/HDPE wood-plastic composite. The effect of steam exploded reed on physical-chemical properties was investigated through this experiment.【Method】 Using the high-density polyethylene as matrix and suitable additives with double spiral extrude, the reed/HDPE wood-plastic composite was fabricated and the mechanical properties of the composite were measured as well. 【Result】Compared with that of reeds without steam explosion, when the steam pressures were 1.2 MPa and 1.5 MPa, the cellulose content increased by 19.2% and 18.1%, the content of acid insoluble lignin reduced by 5.5% and 1.0%, the content of holocellulose decreased by 6.1% and 12.7%, soluble sugar content increased by 4.51% and 7.64%, respectively, and a large amount of hemicelluloses substantial degraded. The fine fiber content significantly increased under a steam explosion of 1.2 MPa, as well as the fiber quality. The maximal tensile strength and flexural strength of the steam-exploded reed/HDPE composite increased by 22.3% and 32.6%, respectively, which satisfied the requires of the national standard(GB/T 24137—2009). The properties of reed/HDPE wood-plastic composites with fiber contents of 50%, 55% and 60% could also reach the national standard. 【Conclusion】It was concluded that the use of steam-exploded reeds to make reed/HDPE wood-plastic composites is a potential way to cost-effectively utilize the waste reeds.