The invention discloses a method for measuring a coating amount of an organosilicon treatment agent on the surface of titanium dioxide. The method comprises 1) determining silicon content S0 of a basematerial in titanium dioxide to be tested, 2) adding different amounts of organosilicon additives into the base material in titanium dioxide to be tested and respectively detecting silicon contents Sx, 3) calculating silicon contents S=Sx-S0 based on the different organosilicon additive use amounts through the detection results obtained by the steps 1 and 2, and calculating the silicon content corresponding to one thousandth of the organosilicon additive, 4) determining silicon content Sy in titanium dioxide to be tested and 5) calculating the organosilicon coating amount of the titanium dioxide to be tested through the detection results obtained by the steps 3 and 4. The method can measure the coating amount of the organosilicon additive on the surface of titanium dioxide, is easy to operate and produces an accurate test result.