The invention discloses a nitrogen foam gel profile control agent and a preparation method and application thereof and belongs to the field of oilfield chemistry. The profile control agent comprises afoam gel skeleton and nitrogen gas distributed in the foam gel skeleton. The foam gel skeleton is obtained through feeding nitrogen gas into the gel. The gel is prepared from 1.5%-2.5% by mass of polyacrylamide, 0.3%-1% by mass of a foaming agent, 1%-3% by mass of a foam stabilizer, 1.5%-2.5% by mass of an organic chromium cross-linking agent and the balance of water through a cross-linking reaction. The foam stabilizer comprises sodium carboxymethyl cellulose or soluble starch. A volume ratio of the nitrogen gas to the foam gel skeleton is 70-95: 1. The profile control agent can seal and profile the medium and low temperature oil layers at 30 to 70 DEG C. The nitrogen foam gel skeleton has good membrane strength and good sealing effects and can greatly improve the mining efficiency of the crude oil.