In order to explore the changes of salted egg yolk aggregation and the key control point in the salting process of Sansui salted egg in Guizhou Province， based on the low-salt salting technology， and through the detection of sodium chloride， changes of protein-related indexes in egg yolk aggregation. The results showed that the 8 days before pickling， ionic bond and hydrophobic interaction increased， the hydrogen bond and disulfide bond decreased， the ratio of α-helix to β-sheet decreased， the ratio of γ-random structure to β-turn increased， the secondary structure of protein changed， and the protein denatured， NaCl alters the structure of the low-density lipoprotein， and the yolk's protein-fat emulsion system was broken， but didn't coalesce to form a gelatinous structure. When salted for 12-16 d， the ionic bond strength decreased， the hydrogen bond， hydrophobic interaction and disulfide bond content increased， the proportion of α-helix structure continued to decrease， the proportion of γ-random， β-sheet and β-turn structure increased slightly， and the protein molecules of egg yolk aggregated， and there was a more obvious sense of loose sand mouth， oil output in more than 40%. During curing for 16-28 d， the structure of the low-density lipoprotein continued to renew， and the water loss from the yolk provided a more favorable environment for the accumulation of lipid molecules to form oil droplets， the dehydration of the yolk and the binding of the protein gels result in the final globular coagulation of the yolk. Through observing the microstructure of egg yolk coagulation part during curing， it was found that the yolk particles are gradually reduced and closely arranged， and there was cross-linking between them， this was the salted egg yolk after the production of a special loose sand feeling the main reason. Finally， it was concluded that curing 12 to 16 days was the key stage for the formation of the special loose sand taste of salted egg yolk and the appearance of oil seepage.