Abstract: Huashu 9 cultivar was used as the experimental object, and six fertilization treatments were set up, including no fertilizer (T₁), traditional organic fertilizer + conventional compound fertilizer (T₂), Woertian bio-organic fertilizer (T₃), Woertian bio-organic fertilizer + slow-release high-potassium fertilizer (T₄), Shengmingyuan fulvic acid bio-organic fertilizer (T₅), and Shengmingyuan fulvic acid bio-organic fertilizer + slow-release high-potassium fertilizer (T₆). A two-year field experiment was conducted to investigate the effects of these different fertilization regimes on soil fertility, agronomic traits, quality and yield of winter-planted potato. The results showed that compared with treatment T₁, treatment T₄ simultaneously increased the contents of soil available nutrients and organic matter. In the first year of the experiment, soil alkaline hydrolyzable nitrogen, available potassium and organic matter increased by 53.09%, 40.73% and 45.68%, respectively. In the second year, available potassium and organic matter increased by 14.19% and 16.46%, respectively. Treatment T₄ significantly promoted plant growth, and plant height increased by 59.58% compared to T₁. This treatment yielded tubers with the highest dry matter and protein contents. Treatment T₄ significantly increased tuber yield and marketable tuber rate. Compared with T₁, the yield increase reached 12.65% and 99.15%, and the marketable tuber rate increase rose by 10.53 and 21.98 percentage points across the two-year trial, with an average yield increase rate of 57.50%. In addition, all fertilization treatments reduced soil pH value. Treatment T₆ significantly increased soil available phosphorus content, and treatment T₅ produced the most prominent increase in tuber vitamin C content. In summary, treatment T₄ (application of 200 kg Woertian bio-organic fertilizer combined with 100 kg slow-release highpotassium fertilizer per 667 m²) achieved optimal effects in boosting potato growth and development, improving soil fertility, raising tuber yield and enhancing tuber quality. It can be recommended as a green, high-quality and efficient fertilization scheme for winter potato cultivation in Guangxi.