The solubility and thermodynamic properties of thiamethoxam in six monosolvents [acetone, dichloromethane, dimethylformamide (DMF), methyl acetate, ethyl acetate, and 1-methyl-2-pyrrolidinone (NMP)] and two binary solvents (DMF + ethyl acetate and NMP + ethyl acetate) were reported. Solubility determinations were performed through the laser monitoring method at T = (278.15-323.15) K and p = 0.1 MPa (except for dichloromethane at 273.15-313.15 K). The measurement results demonstrated that the solubility of thiamethoxam in all of the six monosolvents and two binary solvents shows a positive relationship with temperature variation, and with the mass fraction of positive solvents (DMF, NMP) in the binary mixed solvents increasing, the solubility of thiamethoxam also increases. Then, the recorded solubility of thiamethoxam in all monosolvents was regressed by lambda h, modified Apelblat, two-suffix Margules, NRTL, and UNIQUAC models, while the solubility of thiamethoxam in two binary solvents was regressed by lambda h, modified Apelblat, three-suffix Margules, NRTL, and UNIQUAC models. Furthermore, by calculating the deviation between the experimental data and the regression data, it shows that the modified Apelblat model can provide more accurate correlation results for the solubility of thiamethoxam in all of the solvents studied.