The invention discloses a method for preparing a thin-type titanium or steel composite plate, and particularly relates to a method for preparing a composite plate manufactured by the titanium steel-based composite plate through explosion and pack rolling. The method is characterized in that in the preparation process of the thin-type titanium or steel composite plate, the titanium or steel composite plate is compounded and formed by the titanium plate and the steel plate through explosion, then two composite plates are folded and welded into a billet body, and then the thin-type titanium or steel composite plate is formed through rolling. The preparation method adopts the explosive composite process, the rolling billet body has high bonding strength after explosive compounding, the titanium or steel composite plate billet is folded and welded for rolling, and the deformation amount is in 4 to 7 times; therefore, the preparation method not only ensures higher bonding strength of the titanium or steel composite plate after rolling, but also ensures the respective thickness requirements, the prepared titanium or steel composite plate has good processing technological property, the explosive composite billets of the titanium plate and the steel plate after pack rolling have good bonding property, the bending test is performed without layering, the titanium plate surface is free from cracks and impurities, and the method has the advantages of higher bonding strength, corrosion resistance and fatigue resistance.