Belonging to technical field of oilfield chemical drilling fluid treatment agents, the invention discloses a preparation method of glyceryl glucoside for drilling fluid. The method includes the steps of: (1) adding glucose and glycerin into a reaction bottle in a mole ratio of 1:4-8, adding a protonic acid loaded load type catalyst accounting for 20%-50% of the mass of glucose, carrying out stirring reaction at 80-120DEG C for 5-10h, and filtering out the load type catalyst to obtain an untreated glyceryl glucoside reaction solution; (2) lowering the temperature of the glyceryl glucoside reaction solution to 40-50DEG C, adjusting the pH value to 8.0-10.0 by a neutralizing agent, performing filtering when the solution is hot, and separating out unreacted glucose, thus obtaining the glucose removed filtrate; and (3) transferring the glucose removed filtrate into a single-port flask, and conducting pressure reduced distillation to remove excess glycerin, thus obtaining a glyceryl glucoside crude product.