In order to explore the rich and diverse sacrificial value system of the Sanxingdui culture and to deeply excavate its cultural connotations, thereby providing concrete evidence of the splendid achievements of the ancient Shu civilization, this paper employs analytical techniques such as three dimensional video microscope, scanning electron microscope (SEM), and micro-FTIR spectroscope to conduct microscopic examination and analysis of the residues on the surfaces of bronze wares unearthed from the No.2 sacrificial pit of Sanxingdui site. The microscopic observation results indicate that the residues possess a distinct warp and weft structure and are locally well-preserved. SEM test reveals that the fibre has a triangular cross-section. Combined with micro-infrared analysis, it can be said that these residual textiles are silk fabric. The results prove the existence of silk in the Sanxingdui culture. It is inferred that silk fabric, bronze wares and gold artifacts jointly constitute the sacrificial system of Sanxingdui culture.