N-glycosylation is a post-translational modification involved in various physiological and pathological processes. The variability of glycosylation modification site is a key indicator of cellular activity, as evidenced by the correlation between the reduction of glycosylation attachment site on serum protein and the severity of congenital disorders of glycosylation (CDGs). Therefore, accurately determining site occupancy rate is crucial for understanding the impact of protein glycosylation on human health.