The invention discloses sustained-release polycarboxylate 
superplasticizer and a preparation method and application thereof.The sustained-release polycarboxylate 
superplasticizer is prepared from, by weight, 50-58 parts of polymethylacrylic acid, 22-30 parts of 
castor beans, 5-12 parts of 
menthone, 8-15 parts of 
chitosan, 1-5 parts of 
potassium ferrate and 33-40 parts of 
formic acid.The 
castor beans are dried, smashed and sieved, 
cyclohexane is added into the sieved castor bean 
powder, sealing heating is conducted, and supernatant liquid is extracted after filtering; the supernatant liquid and 
chitosan are mixed, sealing heating is conducted, and a mixture A is obtained; polymethylacrylic acid and 
formic acid are mixed, deionized water is added, heating and stirring are conducted, 
menthone is added, heating and stirring are conducted, and a mixture B is obtained; the mixture A and the mixture B are mixed, and after heating and stirring are conducted, 
potassium ferrate is added, heating is conducted, and the sustained-release polycarboxylate 
superplasticizer is prepared.The sustained-release polycarboxylate superplasticizer has sustained-release performance, the water reducing efficiency is higher, good water reducing performance and 
slump retaining performance are shown, the sustained-release polycarboxylate superplasticizer also has the defoaming function, sources of the raw materials are wide, the production technology is simple, cost is low, no environment 
pollution is caused, and the sustained-release polycarboxylate superplasticizer is suitable for industrial production.