Potassium is one of the major elements in seawater. Research on the structure of potassium sulfate aqueous solution is helpful in explaining the microscopic mechanism of its solubility, thereby providing theoretical guidance for the separation and purification of potassium salt in seawater. In this paper, the microstructure of K2SO4 aqueous solution with different mass fraction was studied using an X-ray diffractometer refitted in the laboratory, Shanghai Synchrotron Radiation Facility device and Raman spectroscopy. The F(Q) obtained from the processing of the X-ray scattering data shows that the double peak near Q=2.5 -1 gradually becomes two peaks of equal intensity, which is associated with the hydrogen bonded network in the liquids. As the mass fraction increases, the peak position near Q=5.0 -1 moves to the right of the coordinate axis. It can be seen from G(r) that the peak at 2.8  tends to broaden with the increase of the mass fractions, which is mainly affected by the O—O interaction. In the Raman spectrum, the intensity of the shoulder peak near 3 200 cm-1 gradually decreases with the increase of solute content, and the overall peak shape becomes narrower in the range of 2 800～3 800 cm-1. The results of deconvolution fitting of Raman spectra show that adding K2SO4 destroys the tetrahedral hydrogen bond configuration of water and slightly promotes the formation of proton-donor hydrogen bonds. The analysis results from X-ray scattering and Raman spectroscopy indicated that the addition of K2SO4 destroyed the original tetrahedral network structure of water molecules.