To study the application of Al/Ni multilayer films in micro/nano ignition apparatus,the propagating velocity of reaction waves in multilayer films was calculated by extended Mann model. The Mann mathematical model was extended by defining the layer thickness ratio to be δ：(2b-1) δ so as to account for multilayer films that have alternating layers with different layer thickness. The propagating velocity of reaction waves in Al/Ni multilayer films was computed and the calculation results agree with the experimental results,which verified the extended model. Results show that there is a critical layer thickness,below which the propagating velocity increases with the increasing of bilayer thickness; while above the critical value,a reverse relation is observed.