In order to develop a technology to harmlessly treat and utilize the rapeseed straw and blue algae, a mixed fermentation of rape straw and blue algae was carried out and the fermented product was used in a potted corn experiment. Mixed aerobiotic fermentation of rapeseed straw and blue algae in four different ratios at a high temperature was set up. According to the fermented maturity level and fertilizer efficiency, a ratio of rapeseed straw to blue algae in 3:2 was selected. The fermented product was applied to the potted corn and compared with the compound fertilizer and no fertilizer control. The growth and quality of corns of the three treatments were analyzed. The results showed that the pH was maintained in the range of 7-9 during the fermentation period in the different ratios, which met the pH requirement of aerobic fermentation. The GI of the fermented product was 80% and above after fermentation for 35 days and reached the standard of complete maturity. The C/N ratio of the fermented product of rapeseed straw and blue algae in the ratio of 3:2 was decreased from 22.9 to 18.4, and the fertilizer efficiency (N+P₂O₅+K₂O) was 6.73%, which was better than the other three groups. The pot experiment results showed that the plant height and leaf area in the fertilization group were significantly higher than the no fertilizer group (P<0.05) at the big trumpet stage. The physiological indexes of maize in the fertilization group were better than those in no fertilizer control. Significant differences in plant height, ear diameter, grains per spike, 100- seed weight, crude fat and crude protein (P<0.05) after harvest were observed. There was no significant difference in growth and quality indicators between the fermented product and compound fertilizer. In conclusion, rapeseed straw and blue algae mixed with the ratio of 3:2 in aerobic composting process were fully decomposed after 35 days. The fermented products can