Earthworms have been studied in many ecosystems, demonstrating their high ecological value. However, there are few studies on the coupling of earthworms to irrigated paddy fields. On this basis, a symbiotic system of irrigated rice and earthworms was established with a wide-ridge cultivation model, and a combination of field experiments and pot experiments was carried out in Southern China. The results showed that the symbiosis of irrigated rice and earthworms in the pot experiment significantly loosened the soil by 5–10 cm, compacted the soil by 10–20 cm, increased the soil pH value by 0–10 cm, and increased the content of soil organic matter by 5–20 cm compared with rice monoculture. Due to the significant increase in leaf area index and grain weight at the mature stage, the white root at the heading and grain filling stages improved significantly, and the yield of irrigated rice also increased significantly by 15.39%. However, in the field experiment, due to the low survival rate of earthworms, the effect of inoculating earthworms was not significant. This study confirmed the beneficial effect of earthworm inoculation on the paddy field ecosystem, and provided a research basis for introducing earthworms into the paddy field ecosystem, realizing the sustainable development of rice cultivation, and ensuring world food security.