In this paper, a multi-radiotherapy method is proposed, which combine proton therapy with boron neutron capture therapy (BNCT). In this multi-radiotherapy method, BNCT is implemented, firstly, in which, the 4He ion and 7Li ion are emitted to destroy the local cell with the radiation of thermal neutron, and normally they stop at inside of the local cell due to their short decay ranges. As a result, a large number of 7L ions are accumulated in the target cell. Then, proton therapy is implemented. Based on the nuclear bombardment reaction 7Li (p, alpha) 4He, beside of the dose from the original proton beam, an additional dose contribution might be induced by two alpha particles (each has energy of about 8.7 MeV) emitted for a target cell. For evaluating the new multi-radiotherapy method, are used the Monte Carlo method. Through analyzing the dose distribution of this multi-radiotherapy method and comparising BNCT and proton therapy, we can conclud that under similar distributions of the physical dose, the multi-radiotherapy method may potentially enhance the radiation destruction efficiency for target cells.