The invention relates to functionalized amino-titanium carbide and a preparation method thereof. The preparation method comprises the following steps: adding a two-dimensional layered nanometer material MXene-Ti3C2 into ultrapure water, and carrying out ultrasound so as to obtain a uniformly-dispersed Ti3C2 dispersion; adding p-phenylenediamine and isoamyl nitrite into the Ti3C2 dispersion, and carrying out a reaction under heating at 60 to 110 DEG C; and after the reaction is completed, cooling the reaction solution to room temperature, and carrying out separation and drying so as to obtain the functionalized amino-titanium carbide. According to the invention, by adopting two-dimensional layered Ti3C2 surface containing hydroxyl and fluorine functional groups, and through heating treatment of a solution of Ti3C2, p-phenylenediamine and isoamyl nitrite and functionalized modification of the hydroxyl and fluorine functional groups on the Ti3C2 surface, an amino group grows on the surface of the two-dimensional layered material MXene-Ti3C2, so the functionalized amino-Ti3C2 is obtained, and surface activity and specific surface area are improved.