High whiteness masterbatch grade ultra-fine calcium carbonate, with whiteness ≥97%, calcium carbonate content ≥98.5%, average particle size D50=1-5μm, uniform particle size distribution, low oil absorption, excellent dispersion and whiteness stability, specially designed for white color masterbatch, filler masterbatch, transparent masterbatch and functional masterbatch production.• It can significantly improve the whiteness, brightness and hiding power of white masterbatch, enhance the color stability and uniformity of masterbatch, reduce the usage of titanium dioxide by 20-40%, significantly reduce the production cost of masterbatch, while maintaining excellent processing performance and mechanical properties of the masterbatch, suitable for PE, PP, PVC, EVA and other resin systems.