The invention discloses a preparation method for an Al/TiAl3 composite, and belongs to the field of composites. The preparation method includes the steps that Ti plates are stacked and rolled; the stacked and rolled Ti plates and Al plates are stacked in a crossed mode according to a certain weight proportion; and the Ti plates and the Al plates which are stacked are heated to 660 DEG C or over, and the temperature is maintained for a certain period, so that the Al/TiAl3 composite with the wild phase TiAl3 distributed dispersedly is obtained. According to the method, the volume fraction of the wild phase TiAl3 can be regulated and controlled within a large range by adjusting the initial Ti/Al proportion, the enhancement effect of the wild phase on a base body is given to full play, it can be guaranteed that the wild phase TiAl3 is evenly distributed in the base body, and the design requirements for the structure and strength of the composite are met. The preparation method has the characteristics that the reaction rate is high, the production cycle is short, the process cost is low, and batched or scale production can be conveniently achieved.