The invention provides a 1050 alloy CTO (computer-to-plate) substrate which comprises the following components in percentage by mass: 0.28-0.32% of Fe, 0.08-0.12% of Si, at most 0.03% of Ti, at most 0.02% of Cu, at most 0.02% of Mn, at most 0.02% of Mg, at most 0.02% of Zn, at most 0.02% of V and the balance of Al. The invention also provides a preparation method of the 1050 alloy CTP substrate. A piezoelectric template control technique, a normal-temperature high-speed multichannel cast-rolling technique, a furnace-out Al-5Ti-B wire matching supersonic grain refinement technique and a continuous rolling technique are utilized to prepare the original cast-rolling structure with abundant uniform and fine crystal grains and dispersedly distributed diphase compounds at the grain boundary, and a processing structure with flat template quality and uniform deformation.