Abstract: 【Objective】 To explore the effect of silicon fertiliser application on cotton agronomic traits, yield and fibre quality in cotton fields under drip irrigation under the membrane, to clarify the mechanism of silicon fertiliser application affecting the growth and development of cotton, and to define the optimal concentration of silicon fertiliser application, so as to provide data support for the promotion and application of silicon fertiliser in cotton. 【Methods】 In this experiment, CK (conventional fertiliser + 0 kg/hm² SiO₂), S₁ (conventional fertiliser + 7.2 kg/hm² SiO₂), S₂ (conventional fertiliser + 14.4 kg/hm² SiO₂), S₃ (conventional fertiliser + 21.6 kg/hm² SiO₂), were used as the planting materials, and silica fertiliser was applied to the cotton fields in the bud stage and flowering stage respectively to analyze the differences in growth and development, yield and fibre quality of the control (CK) and cotton fields with the application of silica fertiliser. hm² SiO₂), and to analyse the differences in growth and development, yield and fibre quality between Si fertiliser application and control (CK) cotton fields. 【Results】 The plant height was lower than that of the control; stem thickness was higher than that of the control; and the application of silicon fertiliser significantly increased the dry matter accumulation of roots, stems, leaves and buds and bolls of cotton (P<0.05). This experiment showed that S₂ application had the best effect. Trace application of silicon fertiliser boll number per plant (8.6%) and single boll weight(10.2%) (P<0.05), and increased cotton seed cotton yield (25.1%) and lint yield (23.0%) (P<0.05). Besides, Length Neatness Index, Specific Breaking Strength and Micronaire were increased to certain extent as well. 【Conclusion】 Drip application of silicon fertiliser with water can promote the growth and development of cotton, increase biomass and yield, and enhance quality.