The paper presents a generalized method for measuring the flow rate of multicomponent flows, which is based on the principle of multichannelling. The paper presents the structure and method of implementing invariant systems for measuring the flow rate and quantity of multicomponent flows. The General Law of transformation of filtration coefficients that are used to measure individual components of the flow is found. The estimation of uncertainty of flow rate measurement results for individual flow components is performed. The results of the study of an invariant system for measuring the flow rate of a four-component flow are presented.