When a droplet laden with surfactant landing on a thin film, spontaneous spreading driven by surface-tension gradient occurs. Affected by the non-linear impact, the initial small disturbances lead to an unstable fingering phenomenon during the spreading, which is closely related to the topographic substrates. Based on the evolution equations of liquid film height and surfactant concentration derived from the lubrication approximation, FreeFEM++ is employed for simulation coding, and the Microsoft MS-MPI runtime library is applied for parallel computing. The influence of the topographic substrates on the instability is examined, the power spectrum is employed to analyze the growth law of disturbance energy corresponding to different wavenumbers, the relation between the Marangoni effect, the capillary effect, and the disturbance energy is investigated, as well as the internal mechanism of the topographic substrate on instability is explored. The results show that the topographic substrates deal little influence on the fingers, but a lot on the region downstream. Disturbance energy with different wavenumbers present different evolution characteristics, and the dominant wavenumbers in this study are 20 and 7. On the notch base, wavenumbers selected from random disturbance is consistent with transient growth analysis (TGA), which means that notch base does not change the wavelength select mechanism. The maximum disturbance energy appears at the position setting the initial condition. Compared with the flat base, the notch base can inhibit the development of disturbances, and the total disturbance energy is reduced to approximately 80%. Whereas the corrugated base can promote the development of disturbances, and the total disturbance energy is increased to about 105%, and the corrugated base has a strong promotion on the disturbances corresponding to specific wavenumbers in the initial stage, which is consistent with TGA. In general, the topographic substrate affects the disturbance energy by changing the concentration distribution of surfactants, thereby influencing fingering phenomena.