The aim of this study was to comprehensively assess the nutritional value and safety of cultured and wild as prawn feed, with the ultimate aim of promoting the rational development and utilization of these sandworms. We investigated and compared the basic nutritional composition of the cultured and wild sandworms, determined their amino acid, fatty acid, and heavy metal contents, and evaluated their infection status with WSSV (white spot syndrome virus) and IHHNV (infectious hypodermal and hematopoietic necrosis virus). The results showed that the fat content was significantly higher in the cultured sandworms than in the wild ones (<0.05), but there was no significant difference in the contents of crude protein, moisture, and ash (>0.05). In both groups of nereids, the ratios of essential amino acids/total amino acids for shrimp feed were about 40%, and the ratios of essential amino acids/non-essential amino acids for shrimp feed were above 60%, which met the FAO/WHO standard for high-quality protein. Based on the amino acid score and chemical score of the two groups, the content of the most limiting amino acid was higher in the cultured sandworms than in the wild ones. The contents of unsaturated fatty acids and highly unsaturated fatty acids were significantly higher (<0.05) in the cultured group[(67.75±3.77)% and (54.11±2.58)%, respectively] than in the wild group[(56.13±6.60)% and (43.28±5.50)%, respectively]. The contents of common heavy metals (chromium, copper, cadmium, lead, arsenic, mercury) were significantly lower in the cultured sandworms than in the wild ones, and the arsenic content in the wild group significantly exceeded the standard. The cultured group was not infected with WSSV or IHHNV, while the wild group was infected with WSSV but not IHHNV. These findings indicated that wild sandworms may carry WSSV. In conclusion, based on their nutritional value and safety, cultured sandworms are better prawn feed than wild sandworms.