White powder or crystals. Relative density 2.534, melting point 880°C, boiling point 938°C. Colorless transparent crystals or white crystalline powder. Easily soluble in water, with a solubility of 6.23 per 100g of water at 20°C; its aqueous solution is alkaline; insoluble in alcohol. The aqueous solution remains stable below 70°C but hydrolyzes to disodium hydrogen phosphate upon boiling. It weathers in dry air and loses water of crystallization at 100°C. It readily absorbs moisture from the air and deliquesces. Forms complexes with alkaline earth metal ions; produces white silver pyrophosphate when encountering Ag+.

It can undergo complexation reactions with metal ions. The pH of its 1% aqueous solution is 10.0-10.2. It possesses the general properties of common polymeric phosphates, such as emulsifying, dispersing, preventing fat oxidation, improving protein binding, and also functions to inhibit oxidation and fermentation of food at high pH levels.