The invention discloses a high-activity nano-calcium carbonate which comprises the following components by mass: 90-96% nano calcium carbonate base material, 0.25-0.5% of coconut oil or palm oil, 1.35-2.5% of soap grains, 2-5% of a fatty acid salt surfactant, 0.4-2% of a nonionic surfactant. The high-activity nano-calcium carbonate has high particle dispersion and lipophilicity, has the activation rate much higher than that of the ordinary activated calcium carbonate and the oil absorption value lower than that of the ordinary activated calcium carbonate, and is nano-calcium carbonate with relatively good activity; the activated nano-calcium carbonate product can avoid the agglomeration of nano-calcium carbonate particles, can reduce the particles to the most primitive state, and can more clearly show characteristics of functional materials when being applied to different high polymers.