Quality traits are crucial for assessing forage quality， impacting directional improvement and variety breeding of forage species， and enhancing livestock production efficiency and sustainable animal husbandry. This study conducted QTL analysis on five nutritional quality traits including water soluble carbohydrate content， neutral detergent fiber content， acid detergent fibe content， phosphorus content and kalium content， in 150 F₂ individuals of sorghum sudangrass hybrid across four environments using interval mapping and a previously constructed high-density genetic linkage map. Candidate genes related to these traits were also identified within the confidence intervals. A total of 198 QTL were detected （LOD≥3）， with 16 QTL repeatedly identified across environments， These 16 stable QTL， contributing 8.8% to 13.7%， were primarily distributed on LG3， LG4， LG6， LG7 and LG8. Seven were major QTL （contribution rate≥10%）， including one for water soluble carbohydrate content， three for acid detergent fibe content and three for kalium content. In addition， 13 candidate genes related to quality traits were identified by gene prediction and functional annotation. Collectively， this study provides a theoretical basis and new insights for molecular breeding and functional gene research of sorghum sudangrass hybrid.