A method for preparing a cyclodextrin metal organic framework (CD-MOF) stable in aqueous phase, including: dissolving β-cyclodextrin and solid potassium hydroxide in deionized water followed by magnetic stirring and ultrasonic treatment at room temperature, addition of methanol and stirring to obtain a reaction mixture; filtering the reaction mixture with a polytetrafluoroethylene membrane filter in a beaker; placing the beaker in methanol vapor to form a β-CD-MOF crystal; washing the β-CD-MOF crystal with ethanol followed by centrifugation and vacuum drying to obtain β-CD-MOF; preparing a β-CD-MOF-active substance complex by impregnation; and preparing an active substance-loaded β-CD-MOF-Tween 80 complex by physical adsorption modification followed by washing with anhydrous ethanol and vacuum drying.