The effect of solubility on a drug is the absorption and bioavailability of the drug in the body. Solubility is an important information for manufacturing drug formulations is also one of the most important indicators for realizing the efficacy of the drug in human circulation. Solubility improvement techniques are categorized into physical modification, chemical modification and other techniques. 1. Physical modification: reducing particle diameter, solid dispersion, nanosuspension, low-temperature technology, inclusions complex formation technology and crystal engineering, etc. are beneficial to the absorption and utilization of drugs. 2. Chemical modification: change PH value, derivatization, complexation and salt formation, etc. to improve bioavailability. 3. Other technologies: surfactants, solubilizers, co-solvents, use of hydrophilic and novel excipients etc. to increase efficacy. Solubility is the basic requirement for drug absorption from the gastrointestinal tract, the correct choice of solubility enhancement methods can maximize the efficacy of the drug, it is recommended to consult a clinical pharmacist.