Quality trait is an important index to measure the forage quality, which plays an important role in the directional improvement and variety breeding of forage. High-quality forage grass can effectively improve the feeding efficiency of livestock and promote the sustainable development of animal husbandry. In this study, using 150 F2 individuals of Sorghum sudangrass hybrrid and their parents as materials. the QTL analysis was performed on five nutritional quality traits WSC, NDF, ADF, P and K by interval mapping methods in four different environments based on the previous constructed high density genetic linkage map of Sorghum sudangrass hybrid. and the candidate genes related to these traits were also screened within the confidence interval. The results showed that a total of 198 QTLs were detected with the threshold of LOD ≥3, of which 16 QTLs were repeatedly detected in different environments, The 16 stable QTLs mainly distributed on LG3, 4, 6, 7 and 8, with a single contribution rate from 10% to 13.7%, of which seven were major QTLs ( PVE > 10% ), including one QTL related to WSC content, three related to ADF content and three for K content. In addition, 13 candidate genes related to quality traits of Sorghum sudangrass hybrid were screened by gene prediction and functional annotation. It will provided theoretical basis and new ideas for further molecular breeding and functional gene research of Sorghum sudangrass hybrid.