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The yellow dextrin/straw fibers composites were prepared using a 150mm×150mm steel mold and JFY50 hot-press machine based on the preparation parameters. The experimental results were analyzed by range analysis method. The optimal level of factors, the primary and secondary factors, the best combination of factors and their levels were obtained. The best combination of factors was tested and verified for the hot pressing temperature of 170℃, the hot pressing pressure of 9.8MPa, the hot pressing time of 20min and the yellow dextrin content of 30g. The yellow dextrin/straw fibers composites were prepared based on the best combination of factors. The flexural strength and the flexural elastic modulus of the composite were 15.34MPa and 2522.78MPa respectively for the optimal combination situation. The experimental results were also analyzed by variance analysis method. The results show that the hot pressing pressure has an evident effect on the flexural property of the yellow dextrin/straw fibers composites, while the hot pressing time has no obvious effect on the flexural property of the yellow dextrin/straw fibers composites.