The invention discloses a multifunctional drug carrier with a high drug loading capacity, as well as a preparation method and application thereof. The drug carrier is prepared from the following raw materials in a certain proportion: trimesic acid, isophthalic acid and cupric nitrate. The preparation method comprises the following steps: (1) weighing the trimesic acid, isophthalic acid and cupric nitrate; (2) preparing a mixed solution containing trimesic acid and isophthalic acid and a cupric nitrate solution; and (3) pouring the mixed solution and the cupric nitrate solution into a reaction kettle, heating the reaction kettle to 110-140 DEG C, adopting temperature programming at a heating rate of 2-4 DEG C/min, controlling the pressure of the reaction kettle to be 100-140kpa, reacting for 10-14 hours to complete the reaction, cooling the product obtained after the reaction to 20-30 DEG C, filtering to obtain a blue solid substance, washing the blue solid substance, and drying at 100-140 DEG C. The drug carrier can be used as a carrier of ibuprofen and doxorubicin at the same time, and can meet different release requirements of ibuprofen and doxorubicin. The preparation method is simple, is convenient to operation, so that the preparation cost is low.