To better exploit and utilize Tenebrio molitor (Yellow mealworms), we evaluated the nutritional composition and food safety of dried larvae and pupae to analyze their nutritional components, amino acid profiles, fatty acid composition, and compared them with common foods to evaluate their nutritional value and safety risk. The results showed that both larvae and pupae exhibited high protein content (43.8% and 48.0%, respectively), high fat content (31.2% and 20.9%, respectively), and rich organic matter, minerals, and vitamins. The amino acid composition of both was the same, and the ratio was reasonable. Both of them contained 17 amino acids (tryptophan not measured), with total amino acid contents of 443.59 mg/g (larvae) and 233.09 mg/g (pupae). Essential amino acids accounted for 38.08% and 37.82% of total amino acids, with essential amino acid indices of 1.06 and 0.49, respectively. Larvae and pupae contained 9 and 8 types of fatty acids, dominated by unsaturated fatty acids (80.36% and 79.99%). Both of them were comprised of 38.80% and 37.84% essential fatty acids, with saturated-to-unsaturated fatty acid ratios of 4.09 and 3.99. Both were rich in mineral elements and vitamins, where potassium was the most abundant mineral (7286.5 mg/kg in larvae; 7399.0 mg/kg in pupae). Heavy metals (lead, arsenic, mercury) complied with national food safety standards. The content of B vitamins was the highest, with total amounts of 5099.0 mg/kg and 5338.9 mg/kg, respectively. In conclusion, yellow mealworms demonstrates high nutritional value without risk of excessive heavy metal content, and holds significant potential for dietary and multi-purpose applications.