The invention relates to a multifunctional fertilizer for preventing and treating open rice glumes. 25-35 parts of decomposed manure, 5-15 parts of humic acid, 2-10 parts of fulvic acid, 2-15 parts of magnesium sulfate, 2-15 parts of chelated zinc, 2-8 parts of Na2B8O13 and 5-15 parts of calcium metasilicate are smashed and screened by a 60-mesh screen, then the mixture is placed in a stirrer to be fully stirred, then 5-20 parts of amino acid powder, 1-5 parts of tillering promoter, 1-5 parts of stem strengthening agent and 0.5-2 parts of ABB pollenin are added, and even mixing and packaging are carried out. Based on the reason for the open rice glumes, organic nitrogen, phosphorus, potassium, multiple microelements, active matter and functional factors are supplemented, the open rice glumes can be effectively prevented and treated, rice resistance can be increased, and the maturing rate and yield can be increased. Multiple organic ingredients are included, the content of organic matter of soil can be increased, soil environment can be improved, soil fertility can be improved, rice tillering can be promoted, resistance and the maturing rate can be increased, and the aim of increasing both production and income is achieved.