In this paper, a rapid and facile method of preparing metal-oxide semiconductor precursor solution using sonochemistry technology is proposed. Compared with the traditional method (water bath above 60 °C for several hours), the efficiency of preparing solution is improved, because sonochemical reaction is found to accelerate the dissolution of solutes and the agitation of solution. The color comparison and thermal gravimetric and differential scanning calorimetry of solution confirme the formation of W-doped zinc tin oxide (WZTO) precursor solution with good performance. The effects of sonochemical reactions on the film structure, surface morphology, optical properties and chemical composition of WZTO thin films are analyzed by atomic force microscopy, X-ray diffraction, UV visible spectrum and X-ray photoelectron spectroscopy. The results show that the film has a smooth surface, an amorphous structure, a high transmittance and more M-O bonding. Hence, a rapid process of preparing WZTO solution (sonochemical treatment for 10 min) and fabricate TFT with high electron mobility (2.7 cm V s) is established, while the corresponding mobility of the traditional method is 1.2 cm V s. The results show that the sonochemical reaction can improve the efficiency of preparing solution by 1800% and it is a fast and efficient method for preparing precursor solutions.