Preparation method of high-viscosity organic silicon defoamer

The invention discloses a preparation method of a high-viscosity organic silicon defoamer. The preparation method comprises the following steps of preparing a silicon grease by using organopolysiloxane, dewatering particles, catalysts and silicon resin under 180-240 DEG C, and stirring and uniformly mixing the silicon grease, polyether modified silicone oil and an emulsifying agent under 72-78 DEG C so as to obtain an oil phase mixture, dissolving a dispersing thickening agent in water; then adding a sodium hydroxide solution to uniformly stir to obtain emulsifying thickening water, adding the emulsifying thickening water into an oil-phase mixture, and carrying out emulsifying stir on the oil-phase mixture under 72-78 DEG C to obtain a coarse emulsifying object; and homogenizing the coarse emulsifying object under 50-55 DEG C to obtain a fine emulsifying object, adding residue water into the fine emulsifying object, stirring and uniformly mixing the fine emulsifying object under room temperature so as to obtain the high-viscosity organic silicon defoamer. The preparation method provided by the invention has the advantages that high-viscosity simethicone is utilized as an emulsifying main raw material, and thus, the obtained high-viscosity organic silicon defoamer has an ultra-strong defoaming speed and an anti-foam effect.