NOVELTY - Preparing high molecular water-absorbing resin (potassium) water retaining fertilizer, comprises e.g. preparing sodium hydroxide aqueous solution, continuously dropping sodium hydroxide solution in acrylic acid, carrying out neutralization reaction, adding acrylamide and potassium sulfate, adding straw powder in reaction solution, stirring, adding methylene-bisacrylamide crosslinking agent, adding ammonium sulfate, heating to process graft copolymerization, adding solidified and dried reaction liquid into a polymerization reactor and aging, polymerizing, naturally drying and crushing.    USE - The method is useful for preparing high molecular water-absorbing resin (potassium) water retaining fertilizer (claimed).    ADVANTAGE - The method shortens the process flow, reduces production time and production cost, solves the problem of soil damage due to the long-term use of the traditional fertilizer, increases the potassium content, does not produce the three wastes (waste material, waste gas, and waste water), does not cause environmental pollution, is safe and environmentally friendly, and produces stable quality product.    DETAILED DESCRIPTION - Preparing high molecular water-absorbing resin (potassium) water retaining fertilizer, comprises (i) preparing 31.7% 22000 g sodium hydroxide aqueous solution, (ii) continuously dropping prepared sodium hydroxide aqueous solution in 27000 g acrylic acid with purity more than 99.5%, carrying out neutralization reaction for 15-20 minutes, adding 2300 g acrylamide, 21000 g potassium sulfate, and then reducing the temperature to 50-60 degrees C, (iii) adding 10400 g straw powder (100-1500 mesh) in reaction solution, stirring and reducing the temperature to 50-45 degrees C, where the rotating speed is 110-120 revolutions/minute, adding 5 g methylene-bisacrylamide crosslinking agent, adding 9 g ammonium sulfate initiator, heating to 65-70 degrees C to process graft copolymerization, where the temperature in reaction process is controlled at 110-115 degrees C, the reaction time is 10-15 minutes, (iv) adding solidified and dried reaction liquid into a polymerization reactor and aging, polymerizing the reaction mixture for 10-20 minutes to solid, and naturally drying, and (v) crushing the solid product to obtain the finished product.