The invention discloses application of proguanil to preparation of an anti-tumor drug and application of proguanil to preparation of a drug for inhibiting primary tumor growth and/or metastatic tumorgrowth; a tumor is a malignant tumor or a benign tumor, wherein the malignant tumor comprises one or more of a bladder tumor, melanoma, mastadenoma, non-Hodgkin's lymphoma, a colorectal cancer, a pancreatic cancer, an endometrial cancer, a prostate cancer, renal carcinoma, renal cell carcinoma, a non-melanoma skin cancer, leukemia, a thyroid cancer, a lung cancer, a cervical cancer, an ovarian cancer, a testicular cancer and a central nervous system tumor; the drug is a proguanil single component or a pharmaceutical composition containing an effective dose of proguanil, a drug mixture or a molecular structure modifier. Study results show that the proguanil realizes a strong anti-cancer effect by key protein AMPK in targeting tumor cell energy metabolism, and the effect of the proguanil ontumor treatment is stronger than that of N-(4-fluorophenyl) biguanidine, metformin and other biguanidine drugs.