The invention relates to a microwave synthesizing process for nano-size silicate based poromeric material, which consists of dissolving aluminium source into water, charging silicon source while agitating, continuously agitating, carrying out microwave processing directly for 3-180 minutes to the reaction solution, microwave heating 3-30 minutes, crystallizing 1-8 days at 60-100 deg C, centrifugally separating, filtering, scouring, dry scouring to neutral, thus obtaining nano-size molecular sieve with adjustable particle size.