The invention discloses a preparation method of a titanium-steel composite board. The titanium-steel composite board with high binding property is prepared through process as follows: blank preparation, surface treatment, painting of a parting agent, symmetrical assembling, electron beam sealing weld, heating, rolling, straightening, cutting partition and the like. Laminations are added to a to-be-composited titanium-steel interface in an assembling process, so that titanium and steel in a composite blank cannot be contacted sufficiently, mutual diffusion of elements in a heating process of titanium and steel is prevented, and generation of brittle phases such as carbide, intermetallic compounds and the like on the interfaces is controlled; then an oxidation film on the interface is damaged by high reduction rolling, a new titanium-steel binding interface is formed and sufficient metallurgical binding is realized, rapid cooling is performed after rolling, regeneration of the brittle phases is inhibited, and the brittle-phase-free titanium-steel composite board with high binding property is prepared. Compared with addition of intermediate nickel foil or copper foil, the preparationmethod has the advantages of being simpler to operate and lower in production cost, and the binding property is higher.