This paper measures the effect of digital Inclusive Finance on Farmers' relative poverty vulnerability under different poverty line standards and its optimal index interval, and reveals the structural differences and mechanism of the impact of digital Inclusive Finance on Farmers' relative poverty vulnerability. It is found that the impact of digital Inclusive Finance on Farmers' relative poverty vulnerability has both "digital dividend" effect and "digital divide" effect, and the two show an inverted "U" relationship; The optimal number to reduce the relative poverty vulnerability of farmers is the inclusive financial index, which is between 108-160. From the perspective of structure, the coverage of digital finance under the lower poverty line standard has a more obvious reduction in the relative poverty vulnerability of farmers; However, under the higher poverty line standard, the depth of digital finance use has a greater degree of mitigation of farmers' relative poverty vulnerability, and its mitigation degree shows a slight increasing trend. At the mechanism level, digital inclusive finance mainly plays an intermediary role by improving farmers' digital skills and risk management ability, reducing residents' income gap, and alleviating farmers' vulnerability to relative poverty.