The invention discloses a preparation method of absorbent polymer which is characterized in high speed rate of liquid absorption, good dispersibility and high dry-touch degree. Acrylic acid is added into sodium hydroxide aqueous solution, which is uniformly mixed with acrylamide and then crosslinking agent, and foam stabilizer aqueous solution is added; while being aerated with nitrogen gas, the solution is ordinally added with polymerization initiator azodi (2-amidinopropane hydrochloride) aqueous solution, ammonium persulphate aqueous solution, sodium bisulfite aqueous solution and uniformly mixed; the aeration of nitrogen gas is stopped, and when the temperature of the solution is raised to 35 to 45 DEG C, the solution is added with foamer aqueous solution and uniformly mixed, so that porous gel is obtained; when the temperature is raised to 100 DEG C to 110 DEG C, the porous gel is put in the temperature environment of 80 to 90 DEG C for two the three hours; after being cooled down, the porous gel is taken out of a container, scissored into pieces, dried, crumbled and filtered, and grains are collected; crosslinking treatment agent is sprayed on the surface of grains, and after stirring and heating, the absorbent polymer is obtained. In three minutes, the volume of saline absorbed by the product prepared by the invention can reach 70 ml/gSAP.