The deliquescence and caking of potassium nitrate cause a loss of materials functionality as well as unqualified products. Therefore, a method that using various surfactants modified potassium nitrate was carried out. The moisture adsorption and anticaking efficiency performances of modified products were investigated. The modified-KNO3 (M-KNO3) was characterized by contact angle measurement, SEM, XRD, FT-IR and XPS. The results showed that the contact angle of potassium nitrate modified by sodium dodecyl sulfate (SDS) reached 109.6 degrees at the required modification parameters, the moisture adsorption capacity of potassium nitrate decreased by 77% and the anticaking efficiency improved to 90%. The formation of the hydrophobic layer on the surface of potassium nitrate based on the chemical bonding between sodium dodecyl sulfate and K+, which effectively prevented the deliquescence and caking of potassium nitrate. This study revealed a valid reaction mechanism model for a series of deliquescence and caking problems of inorganic salts. (C) 2019 Elsevier B.V. All rights reserved.