Abstract: The object is to provide a method for producing an organosilicon compound having a trifluoromethanesulfonyloxy group (CF3SO3) such as di-tert-butylsilyl bis(trifluoromethanesulfonate), which does not generate harmful HCl gas, does not need to be performed at a high temperature of about the boiling point of trifluoromethanesulfonic acid (162° C.), and gives a good yield. The present invention is a method for producing an organosilicon compound of formula (II) (wherein each R is the same or different and represents a C1-C6 linear or branched alkyl group, a C3-C8 cycloalkyl group, a phenyl group, or a combined group thereof; OTf represents a CF3SO3 group; and W represents a hydrogen atom or OTf) wherein a di-substituted silane compound of formula (I) (wherein R is as defined in formula (I)) is reacted with trifluoromethanesulfonic acid.