The invention discloses a nickel-based alloy ultra-thin plate and a preparation method thereof. According to the percentage composition of the chemical components of alloy, the nickel-based alloy ultra-thin plate comprises 20%-30% of Fe, 20%-25% of Cr, 1.3%-1.9% of Al, 1.2%-1.6% of Ti, 0.5%-0.7% of Nb, 0.8%-1.0% of W, 0.5%-1.0% of V, 0.5%-0.7% of Mn, 0.2% of Mo, 0-0.02% of Zr, 0-0.15% of Si, 0-0.03% of C, 0.005%-0.04% of N, 0-0.004% of B, and the balance Ni and other inevitable impurities. The preparation method includes the steps of alloy smelting and casting, homogenization treatment, cogging, hot rolling, strong deformation cold rolling, finish rolling, recrystallization heat treatment and the like. By adoption of the mode of combining strong deformation rolling with heat treatment structure regulation and control, superfine crystallization and nano precipitated phase reinforcement of the alloy structure are realized, and the nickel-based alloy ultra-thin plate prepared through thepreparation mode has super strength and good ductility and toughness. Compared with the prior art, the nickel-based alloy ultra-thin plate prepared through the preparation method in the invention is simple in alloy composition, high in performance of ratio and long in service life, the preparation method and production technology are simple, industrialization scale production can be achieved withcommon industrial equipment, production efficiency is high and industrial application prospects are broad.