Abstract: To explore the optimal technology for improving acidified soils in Zhangpu County, a field experiment was conducted on yellow sandy soil, which involved applying organic fertilizer（9000 kg·hm⁻²）and oyster shell soil conditioners at different rates（0, 1500, 3000, and 4500 kg·hm⁻²）based on the conventional fertilization for cauliflower. The results showed that, compared with conventional fertilization, the treatments of combining organic fertilizer with oyster shell soil conditioners at different rates increased the soil pH by 0.12-1.09 units, the soil exchangeable calcium by 2.4-34.7 mg·kg⁻¹, and the soil available potassium by 4.6-14.6 mg·kg⁻¹ in the acidified soil with an initial pH of 4.8. Among them, the treatment with 4500 kg·hm⁻² of oyster shell soil conditioner showed the most significant effect, followed by the treatment with 3000 kg·hm⁻². The yield assessment indicated that, in comparison with conventional fertilization, the application of organic fertilizer combined with oyster shell soil conditioners at different rates increased cauliflower yield by 6.7%-13.9%, with the treatment using 3000 kg·hm⁻² of oyster shell soil conditioner showing the most significant yield-increasing effect. Considering comprehensively the effects of acidification improvement, soil fertility enhancement, yield increase, and income growth, the optimal technical measure for improving acidification and enhancing fertility of acidified soils in this region is to apply 9000 kg·hm⁻² of organic fertilizer and 3000 kg·hm⁻² of oyster shell soil conditioner on the basis of conventional fertilization.