Preparing method of impervious lost circulation additive

The invention discloses a preparing method of an impervious lost circulation additive, and belongs to the technical field of impervious lost circulation additive preparations. The preparing method comprises the steps of mixing and stirring potassium metasilicate and the like with distilled water, then adding aluminum silicate and the like into the mixture to be subjected to heat preservation to prepare a mother solution, putting micarex into the mother solution, conducting still standing under zero DEG C, immigrating the mixture to a micarex grotto gap, injecting the mother solution into the mixture to be subjected to natural crystallization so as to obtain a crystalline body, conducting drying and powder grinding to obtain a component A for use, then taking bisphenol A, dichloromethane and the like to be subjected to reaction to prepare a glue solution, using water to wash the glue solution to obtain a liquid phase, conducting drying and extrusion prilling on the liquid phase to obtain particulate matter, co