The rules of nutrient absorption and its relationship with the accumulation of medicinal composition were studied , in order to clarify the types of nutrient elements that affect the accumulation of medicinal components and provide a theoretical basis for the scientific formulation of fertilization plans and standardized planting of Paeonia lactiflora in the Hexi region. The 4-year-old Paeonia lactiflora were taken as the research material in in Gufeng Town, Gulang County, Gansu Province ,the dry matter accumulation characteristics, nine nutrient elements and three types of medicinal composition of Paeonia lactiflora at different growth stages were studied, and the correlation between the content of effective components in Paeonia lactiflora and nutrient elements was explored with field experiments. The results showed that the accumulation of dry matter in the roots of Paeonia lactiflora showed a trend of first decreasing and then increasing. The dry matter of the entire plant of Paeonia lactiflora gradually increases with the growth period, and the period of 90 to 130 days after emergence is the fastest period for dry matter accumulation , accounting for 79.29% of the total accumulation. It was a critical period for the growth of Paeonia lactiflora. The nitrogen and potassium content showed decreasing trend, while the phosphorus content showed significant increasing trend in the aboveground parts of Paeonia lactiflora at different growth stages. The nitrogen and phosphorus content showed decreasing trend in the roots, while the potassium content changed little. The total accumulation of aboveground and root nitrogen reached their highest levels at 130 and 150 days after emergence, respectively .The accumulation of aboveground phosphorus reached its maximum at 150 days, while the accumulation of root phosphorus reached its peak at 30 and 150 days after emergence. The accumulation of aboveground potassium reached its maximum at 70 days and the accumulation of root potassium reached its peak at 150 days after emergence. The nitrogen and potassium contents in the aboveground parts were higher than those in the roots at different growth stages, while the phosphorus content was lower than the roots before 90 days and higher than the roots after 110 days after emergence. The accumulation of paeoniflorin and albiflorin in roots first increased, then decreased, and finally stabilized. The accumulation of polysaccharides showed a trend of high low high.The content of paeoniflorin is highly significantly positively correlated with nitrogen, calcium, and copper content, and significantly positively correlated with potassium content. The content of albiflorin is highly significantly positively correlated with nitrogen, potassium, calcium, and copper content, while there is no correlation between polysaccharide and various nutrients.The maximum efficiency period of nitrogen, phosphorus, and potassium nutrition was 110-150 days after emergence. Nitrogen and potassium fertilizers was beneficial for the accumulation of root biomass. Adding Ca and Cu elements to fertilization could effectively promote the accumulation of effective components in Paeonia lactiflora. Paeonia lactiflora should be harvested in the cold and cool mountainous areas of Hexi in mid to late September (after September 16th).