Provided are a method of manufacturing an aluminum-zinc-based alloy sheet using twin-roll casting and an aluminum-zinc-based alloy sheet manufactured thereby. Specifically, a method of manufacturing an aluminum-zinc-based alloy sheet, including preparing a melt by melting elements corresponding to an aluminum alloy including 0.5 wt % to 10 wt % of zinc, inevitable impurities and aluminum as a balance (step 1); and twin-roll casting by introducing the melt prepared in step 1 between a pair of rotating cooling rolls (step 2), and an aluminum-zinc-based alloy sheet manufactured thereby are provided.The present invention may manufacture an aluminum-zinc-based alloy sheet, in which twin-roll casting is known to be difficult due to a wide solid-liquid coexistence region, by twin-roll casting by using cooling rolls having high thermal conductivity and controlling a reduction force by the rotational speed of the rolls.