The invention relates to a preparation method of a double-polypeptide modified europium doped gadolinium oxide nanorod for in vivo target reinforcement of magnetic resonance-fluorescence dual-mode imaging and restraining of growth of early-stage brain glioma. The preparation method comprises the following steps: dissolving gadolinium nitrate and europium nitrate, conducting reaction on the dissolved gadolinium nitrate and europium nitrate and strong base, and obtaining a europium doped gadolinium hydroxide nanorod through heating growth; sintering at a high temperature to obtain a europium doped gadolinium oxide nanorod; then, through surface hydroxylation, amination and pegylation, connecting an RGD polypeptide and CTX through the sulfhydrylation technology. According to the invention, the technology is simple, the condition is controllable, the operation is easy, the nanorod product is small in size (the nanorod is about 80 nanometers in length and about 25 nanometers in diameter), and low in draw ratio; the nanorod modified by two polypeptides, namely RGD and CTX, can penetrate through double barriers, namely blood brain and hemangioma, of a brain tumor, has excellent nuclear magnetism T1 mode relaxation efficiency, fluorescence characteristic, and early-stage glioma target and restraining characteristics and can be used for clinical diagnosis and treatment of early-stage brain glioma.