In order to study the amino acid and fatty acid compositions of different parts of yak meat and systematically analyze the differences in nutritional characteristics of these parts of yak, yak carcasses were finely segmented, and the characteristic differences in amino acid and fatty acid compositions of 20 parts of yak meat were analyzed, and the nutritional value of each part of yak was evaluated by using methods such as amino acid ratio coefficients, standard pattern spectrum and whole egg pattern spectrum ratio of the Food and Agriculture Organization/World Health Organization. The nutritional value of each part of yak meat was evaluated by using amino acid ratio coefficient, Food and Agriculture Organization of the United Nations/World Health Organization (FAO/WHO) standardized pattern spectrum and whole egg pattern spectrum ratio, etc. A total of 18 amino acids and 35 fatty acids were detected in the 20 parts of yak meat, and the smallest Ratio Coefficient of Essential Amino Acids (RC) was with tryptophan, which is the first limiting amino acid, and the Scores of RC (SRCs) of all the parts were over 77, among which the SRC of yak’s tendon part was the highest (84.21), indicating that this part had a relatively high nutritive value; and the fatty acid with the highest content was C18:1n9c, which was especially high in the tendon part of the plate with 38.5%. The highest content of fatty acids was with C18:1n9c, especially in the tendon part (38.76%), with the ratios of monounsaturated fatty acids/saturated fatty acids ranging from 0.81 to 1.08, and the ratios of polyunsaturated fatty acids/saturated fatty acids ranging from 0.07 to 0.50. The amino acid patterns of all parts of yak meat conformed to the recommended patterns of the FAO/WHO, and there were some differences in amino acids and fatty acids among the different parts of yak meat. The comprehensive evaluation showed that the tendon had a high nutritive value. The results of this study provide a theoretical basis for the quality evaluation and deep processing of yak meat.