The general dispersion relation of width mode of the magneto-static surface wave (MSSW) propagating in YIG multilayer films with finite sample width and arbitrary parameters is established. The theory includes all the situations of MSSW dispersion control by multilayer films and is in a better agreement with the actual situation. The dispersion of MSSW width mode in [(YIG/GGG)10/metal] periodic multilayer films were numerically investigated by applying the theory. Numerical results showed that the main working mode of MSSW propagating in multilayer YIG films is the first order width mode, the dispersion of MSSW can be controlled efficiently by the multilayer periods and the parameters of each layer. It also is influenced by the sample width.