The BST thin films were prepared by RF magnetron sputtering with two different processes of high-temperature sputtering or low-temperature sputtering followed by high-temperature annealing processes. The effects of the two sputtering processes on the structure, micromorphology and dielectric properties were studied. The crystal structures of BST thin films were characterized by X-ray diffraction (XRD). The micromorphology and surface profileof samples were analyzed by scanning electron microscopy (SEM) and surface profilometer. The uniformity of component distribution was showed by energy dispersive spectroscopy (EDS) analysis. Finally, the dielectric constant bias characteristic of the BST film was obtained bymeasuring the capacitance-voltage (C-V) curve.The results show that, compared with the BST thin film prepared by the low temperature sputtering and high temperature annealing process, the BST thin film prepared by the high temperature sputtering has better crystallinity, higher density, smoother surface, and uniform film composition distribution. Therefore, the BST thin filmsprepared by thehigh-temperature sputtering process have better properties.At a frequency of 300 kHz, the dielectric constant of the BST film prepared by high-temperature sputtering is 127.5-82.0, and the tunability is 23.86%-27.9%.