The invention discloses an aluminum substrate material of a copper-aluminum composite plate strip, simultaneously relates to the copper-aluminum composite plate strip and a processing method thereof, and belongs to the technical field of a metal plate strip processing. According to the invention, the copper-aluminum composite plate strip adopts the aluminum substrate material containing Si, Fe, Cu and Mn and a copper clad material; the strength of the aluminum substrate material is increased by adding elements of Si, Fe, Cu and Mn, and the processing property of the aluminum material is changed to be identical to the processability of the copper clad material, so that the problems that the soft annealing temperatures of copper and aluminum are different in the plate strip manufacturing process and composite materials are difficult to be punched are solved; and the composite material can reach deep drawing properties of pure copper and pure aluminum. In a process of processing the plate strip, a billet is prepared through an oxygen-free high-pressure continuous casting, and then the billet is subjected to processes, such as cold rolling, intermediate annealing, finish rolling and finished product annealing, so that the integral property of the plate strip is further improved. The copper-aluminum composite plate strip processed by the method is high in production efficiency, stable in quality, advanced in technology, and remarkable in economic benefit, and saves energy and materials.