Recycling and efficient use of organic-waste is a pressing issues facing the actual production. To provide a theoretical basis for scientific and rational management and improving the red soil fertility and biological function, changes of soil nutrients and biological properties were studied by incubation experiment in this study. The results showed that there were significant effects on physicochemical and biological properties of red soil. Treatment of alkali slag could alleviate the acidification of red soil. Although there were no obvious effects between treatments on alkali-hydrolyzed nitrogen, straw decomposition promoted by additive, especially FeSO4 could improve the available phosphorus and potassium. After 60 d, the urease and invertase activities of additives treatments reached peak values and was in an order of additives straw decomposition > none additives straw decomposition > control. The MBC and MBN reduced first and then increased during incubation time. In the end, the MBC of alkali slag treatment was 46.5% and 286.2% higher than those of none additives and control respectively, but the MBN of FeSO4 treatment was highest in our study. The carbon utilization abilities of soil microbial were improved by treatments, especially by the alkali slag treatment. Our results suggested that the straw decomposition promoted by alkali slag could enhance the fertility and biological function of red soil obviously, this will provide scientific reference for improving the quality of red soil.