It is well known that investigation on exact solutions of nonlinear fractional partial differential equations (PDEs) is a very difficult work compared with integer-order nonlinear PDEs. In this paper, based on the separation method of semi-fixed variables and integral bifurcation method, a combinational method is proposed. By using this new method, a class of generalized time-fractional thin-film equations are studied. Under two kinds of definitions of fractional derivatives, exact solutions of two generalized time-fractional thin-film equations are investigated respectively. Different kinds of exact solutions are obtained and their dynamic properties are discussed. Compared to the results in the existing references, the types of solutions obtained in this paper are abundant and very different from those in the existing references. Investigation shows that the solutions of the model defined by Riemann-Liouville differential operator converge faster than those defined by Caputo differential operator. It is also found that the profiles of some solutions are very similar to solitons, but they are not true soliton solutions. In order to visually show the dynamic properties of these solutions, the profiles of some representative exact solutions are illustrated by 3D-graphs.