NOVELTY - Preparation of methotrexate/layered double hydroxide nanocomposite material includes putting pre-milled divalent and trivalent metal salts in a mortar; adding methotrexate; dropping alkaline solution; uniformly mixing the divalent metal salt, trivalent metal salt, methotrexate, and alkaline solution; grinding at constant speed from initial viscous state to dry state; centrifuging; washing; uniformly grinding the mixture with distilled water to obtain precursor of methotrexate/layered double hydroxide; dispersing the obtained precursor in water; peptizing; and drying.    USE - Preparation of methotrexate/layered double hydroxide nanocomposite material (claimed).    ADVANTAGE - The method uses the mechanical chemical method to prepare product with good morphology and good monodispersity. It is green and environment-friendly.    DETAILED DESCRIPTION - Preparation of methotrexate/layered double hydroxide nanocomposite material, where layered double hydroxide comprises divalent metal ion (M2+) and trivalent metal ion (M3+), and interlayer comprises anion, where M2+ is magnesium ion (Mg2+), manganese ion (Mn2+), iron ion (Fe2+), cobalt ion (Co2+), nickel ion (Ni2+), copper ion (Cu2+), or zinc ion (Zn2+), M3+ is aluminum ion (Al3+), chromium ion (Cr3+), manganese ion (Mn3+), iron ion (Fe3+), cobalt ion (Co3+), or nickel ion (Ni3+), and the interlayer anion is one or two of hydroxide ion (OH-), carbonate ion (CO32-), sulfate ion (SO42-), chloride ion (Cl-), and nitrate ion (NO3-), comprises chemical-mechanical method comprising:    (A) respectively pre-milling the divalent metal salt and trivalent metal salt until uniformly mixed;    (B) preparing alkaline solution with 8-12 mol/L concentration;    (C) respectively weighing the divalent and trivalent metal salts at M2+ /M3+ mol ratio of 2:0.8-2:1.5; putting in a mortar; adding methotrexate, where the mol ratio of trivalent metal salt and methotrexate (MTX) is 2:0.5-2:2 (M3+/MTX ); dropping alkaline solution, where the mol ratio of alkaline solution and trivalent metal salt is 7:1-15:1 (OH-/M3+); uniformly mixing the divalent metal salt, trivalent metal salt, methotrexate, and alkaline solution; grinding at constant speed from the initial viscous state to dry state; centrifuging; washing; and uniformly grinding the mixture for 3-4 times with distilled water to obtain precursor of methotrexate/layered double hydroxide; and    (D) dispersing the obtained precursor in water to prepare 0.2-4 mol/L precursor solution; putting the precursor solution into a reaction kettle; peptizing; and drying the obtained product to obtain methotrexate/layered double hydroxide nanocomposite material.