There is a great difference between the conditions of laboratory-scale synthesis of aqueous solution polymerizationand those of industrial production at home and abroad, and there is still no simple and feasible proper guidance method. Taking the scale-up synthesis of the water reducer for cementation as an example, and according to the characteristics of the synthesis of the water reducer, this study selects the scale-up criteria with the synthesis process conditions as the main part on the principle of similarity scale-up; hence, has set up a stirring power Np amplificationmodel, and develops the scale up synthesis method suitable for aqueous solution polymerization. The scale-up synthesis method was used in lab to test the AMPS water reducer by 2 to 10 times volume, and the resultingproducts showed that, compared with the small scale test, the differences in the best product conversion rate and the 120°C API water loss were 5% and 10mL respectively. The molecular weight and infrared test results indicated they are the same products. The method has also been successfully used to guide 50L pilot production with stable the product quality, and the physical properties and cementing slurry application test results of the product were consistent with the small test. The results show that the scale-up synthesis method can effectively reduce the influence of the scale-up effect on scale-up synthesis.