Abstract: With the advent of the Internet of Things era, there is an increasingly urgent demand for micro power supplies that can be manufactured to be compatible with integrated circuits. All-solid-state thin-film batteries (ASSTFBs) become an ideal on-chip power supply that can be integrated with integrated circuits due to their thin-film manufacturing process. Lithium-sulfur battery has a very high theoretical energy density, and if it can be applied to ASSTFBs, their energy density can be expected to be significantly increased. However, the low melting point of elemental sulfur and its inherent sluggish dynamics resulted in inexperience in the preparation of S thin film and hindered their integration into ASSTFBs. Therefore, the VGs-S composite thin film was fabricated by using a tubular furnace thermal evaporation method to deposit active material sulfur uniformly into vertical graphene nanosheets (VGs) thin films. The results show that the VGs-S composite thin-film cathode has a high discharge capacity, which could deliver an initial discharge capacity of 55.3 μAh cm⁻² at 12.7 μA cm⁻²_. It can also stably circulate 1000 cycles at the higher current density of 127.2 μA cm⁻², and the average attenuation per cycle is only 0.036%. This work can provide a novel constructing strategy of sulfur-based thin-film cathode for high-energy-density ASSTFBs.