A continuous process for preparing organomodified polysiloxanes by the transition metal-catalyzed addition of polysiloxanes containing SiH groups onto substances containing C—C multiple bonds, in particular a process for the continuous hydrosilylation of substances containing C—C multiple bonds, which comprises introducing the reactants, in the presence or absence of a homogeneous or heterogeneous catalyst, into a loop-like, heatable and coolable reaction circuit which has a static mixing element and/or a dynamic mixing element to mix starting materials and product formed, leaving the reaction mixture in the reaction circuit until a predetermined degree of conversion has been reached and subsequently transferring the reaction mixture still containing starting materials to a tube reactor to complete the reaction and taking it off via a receiver. In addition, a suitable industrial apparatus for carrying out the process of the invention is described.