The invention relates to the technical field of the neurology department, in particular to a medicine for treating neurasthenia. The medicine is prepared from components in percentage by mass as follows: 2%-4% of trimetozine, 1%-5% of midecamycin, 30%-40% of nabumetone, 15%-17% of taurine, 2%-6% of ketotifen, 23%-25% of catechol, 3%-5% of nicotinamide, 1%-3% of oleanolic acid, 1.5%-2.5% of quetiapine and 2.5%-11.5% of loxoprofen. The invention also discloses a preparation method of the medicine. The medicine comprises the steps as follows: step 1, preparing materials; step 2, drying and grinding the materials into powder; step 3, performing crushing treatment; step 4, preparing an ethanol solution; step 5, performing concentration and drying; step 6, extracting the medicine. The medicine can effectively improve organism functions and enhance immunity, has significant effects on the neurasthenia, has no toxic or side effects on the human body, can relieve anxiety and cognitive defect symptoms and has effects of clearing heat, reducing internal heat, regulating flow of vital energy and dredging collaterals.