In this study, the data on solid−liquid equilibrium of L-prolinamide were studied using the gravimetric method. The solubility of L-prolinamide was measured in ten pure solvents (tetrahydrofuran, n-heptane, n-propanol, acetone, acetonitrile, ethyl acetate, N,N-dimethylformamide, n-hexane, cyclohexane, and isopropanol) and three binary solvent mixtures(ethyl acetate + tetrahydrofuran, n-heptane + ethyl acetate, and n-hexane + acetone) in the temperature range of 278.15−323.15 K at atmospheric pressure. The experimental values showed that the solubility increased with the increase of temperature in all solvents. The solubility data in different pure solvents were fitted using the modified Apelblat model and the Buchowski−Ksiazaczak λh model. For the solubility data of three binary solvent mixtures, the modified Apelblat model, the combined nearly ideal binary solvent/Redlich−Kister (CNIBS/R−K) model, and the Jouyban−Acree model were used to fit. In all four models, the modified Apelblat model had a better correlation with the solubility of L-prolinamide weather in pure solvents or binary solvent mixtures. The experimental results showed that n-heptane and n-hexane could be used as antisolvents, which could be used in the purification process of L-prolinamide and guide the large-scale production of many drugs such as Alpelisib in industries.