The overview of a mathematical model for multicast routing supporting shared explicit reservation of link resource was presented, which is introduced by linear expressions that responsible for ensuring the connectivity of the calculated multicast routes, as well as the absence of loops in them. The novelty of the model consists in introducing conditions for preventing congestion of communication links when implementing a shared explicit reservation, in which a link resource is allocated to several flows simultaneously, but the list of these flows is strictly defined. The task of routing multicast flows supporting shared explicit reservation of link resource is formulated as an optimization problem of mixed integer linear programming. The use of the proposed model makes it possible to exploit the available link resource more efficiently (on average, from 15 to 25%) by ensuring the consistency of solutions for multicast routing tasks and organizing of the shared explicit reservation.