Sodium silicate sand with high fluidity and preparation method thereof

The invention aims at providing sodium silicate sand with high fluidity and a preparation method thereof. The sodium silicate sand is characterized in that the modulus of employed sodium silicate is 2.2-2.8, when the sodium silicate is prepared, 1%-10% (wt%) of an alkali metal inorganic substance and 5%-15% (wt%) of an amorphous phosphate are added into sodium silicate. By modifying sodium silicate and adding a fluidity promoter during sand mixing, the fluidity of sodium silicate sand is improved, the problem of bad fluidity of sodium silicate sand is solved, and great meaning is provided for application of sodium silicate sand and development of green casting.