Abstract: The effects of different amounts of BioSilAc foliar silicon fertilizer on the yield of maize and its influencing factors were explored in this paper, in order to provide theoretical guidance for the high-yield cultivation of maize in the red soil area of northern Fujian. By taking Zhongke Xiangtiannuo (918) as the test object, and on the basis of conventional fertilization, three treatments were set up: T₀ (sprayed with 300 L ·hm^-2 water, CK), T₁ (sprayed with 300 L ·hm^-2 BioSilAc foliar silicon fertilizer with a concentration of 1.33g·L^-1), and T₂ (sprayed with 300 L ·hm^-2 BioSilAc foliar silicon fertilizer with a concentration of 2.67 g·L^-1), thus to analyze the effects of different dosages of BioSilAc foliar silicon fertilizer on the growth and nutrient absorption of maize. The results showed that compared with T₀, the treatments sprayed with different amounts of BioSilAc foliar silicon fertilizer had no significant effect on the agronomic traits such as the leaf numbers and plant heights of maize. Compared with T₀, the yield of maize kernels by T₁ and T₂ treatment increased by 7.9% and 10.9%, respectively, and the absorptive capacity of phosphorus in maize kernels increased by 3.2% and 16.6%, respectively. According to the analysis of principal component regression model, the phosphorus accumulation in maize kernels played a leading role in increasing the yield of maize. In summary, the application of BioSilAc foliar silicon fertilizer at different dosages was helpful to increase the phosphorus absorption of maize kernels in the red soil area of northern Fujian, and thus increase the yield of maize, especially under the application of 300 L ·hm^-2 BioSilAc foliar silicon fertilizer with a concentration of 2.67 g·L^-1, the yield-increasing effect would be better.