To investigate the effects of different organic fertilizers on the yield and quality of purple sweet potatoes, a field experiment was conducted in 2023 at the experimental base of Tai’an Academy of Agricultural Sciences using ‘Taizishu 1’ as the test sweet potato variety. Six treatments were designed, including no fertilization, single chemical fertilizer, and 50% reduced chemical fertilizer combined with pig manure, cow manure, sheep manure, and chicken manure. The study analyzed the impacts of these treatments on agronomic traits, dry matter distribution, yield, and quality of purple sweet potatoes. The results showed that the purple sweet potato stem treated with pig manure had the thickest diameter, at 14.95 cm, an increase of 15.71% compared to the single chemical fertilizer treatment; the aboveground dry weight of sheep manure treatment was the heaviest, at 197.62 g, 30.33% higher than the single chemical fertilizer treatment; the proportion of dry matter distribution in the tubers treated with cow manure was the highest, at 71.82%, which increased by 11.47% compared to the single chemical fertilizer treatment; the yield and commodity rate of purple sweet potato tubers treated with pig manure were the highest, which were 48607.95 kg/hm² and 79.25%, respectively; the soluble sugar content in purple sweet potato tubers treated with pig manure was the highest, at 38.75 mg/g, significantly higher than other treatments. Research has shown that the combination of pig manure and chemical fertilizers can promote the coordinated growth of the aboveground and underground parts of purple sweet potatoes, promote the rational distribution of dry matter, and thereby increase the quantity, rate, weight, yield, and soluble sugar content of commercial sweet potatoes. The effect is superior to the combination of other organic fertilizers and chemical fertilizers. This research provides a theoretical foundation for high-quality and high-yield cultivation techniques of purple sweet potatoes.