Abstract: The problem of fault-tolerant routing on hypercube is studied on the basis of the method of adding bus. Let BH_n be a modified n-dimensional hypercube which is added with multiple buses, and F be the set of its faulty nodes,|F| ≤ n. According to the conclusion in this paper, the diameter of small system of BH_n; reduces from n+2 to 3, and that of large system reduces to not more than (n/3) + 6. It is well known that, n + 2 > (n/3) + 6, for arbitrary n > 6, so the fault-tolerance capability of the modified hypercube is improved than that of hypercube when n > 6.