Cold-waterlogged paddy fields across Jiangnan rice-growing regions belong to low-yield paddy fields. Deep-narrow drainage is beneficial for such fields in improving grain yield. In this paper, the effects of long-term deep-narrow drainage on the characteristics of cold-waterlogged paddy soil and the yield of rice were studied, using a 30-year investigation system in Shunchang County, Fujian Province. The results showed that compared with the typical cold-waterlogged paddy soil (more than 75 m distance from drainage), the soil Eh was increased by 288.2%-323.4% in long-term deep-narrow drainage paddy soil (within 25 m distance from drainage). And the water contents were decreased by 7.5%–36.2% and the concentrations of total reducing agents, Fe²⁺ and Mn²⁺ were decreased by deep-narrow drainage. The pH, MBC and MBN contents were increased by 0.13–0.69, 66.0%–99.0% and 77.0%–275.1% respectively in paddy soils within 25 m distance from deep-narrow drainage, the nutrient availability and soil tilth were improved and then the agricultural machinery could work in the field within 25 m distance from drainage. The intensity of soil reduction is one of the key elements for crop growth in cold-waterlogged paddy fields. The mineralization of soil organic matter and the activity of soil microbe were improved by drainage and then crop yields were increased by 6.6%–20.7%, and the increasing range of yield was decreased with the distance increasing from drainage. In a word, there was a significant positive impact of deep-narrow drainage within 25 m distance on the characteristics of cold-waterlogged paddy soil and the yield of crop.