The invention discloses a polyethylene glycol modified glycyrrhetinic acid and curcumin compound used for resisting hepatic carcinoma, and a preparation method thereof. The preparation method comprises the following steps: (1), the preparation of methoxy polyethylene glycol-tosylate (mPEG-OTs); (2), the preparation of methoxy polyethylene glycol-phthalimide (mPEG-PI); (3), the preparation of single-ended amino methoxy polyethylene glycol (mPEG-NH2); (4), the preparation of methoxy polyethylene glycol-glycyrrhetinic acid (mPEG-18beta-GA); (5), the preparation of polyethylene glycol modified glycyrrhetinic acid and curcumin compound (mPEG-GA and CUR compound), wherein the yield of the mPEG-OTs can reach 84.54 percent or above, the yield of the mPEG-PI can reach 88.96 percent or above, the yield of the mPEG-NH2 can reach 88.72 percent or above, and the yield of the mPEG-18beta-GA can reach 82.43 percent or above. The purity of the mPEG-OTs can reach 95.74 percent or above, the purity of the mPEG-PI can reach 96.88 percent or above, the purity of the mPEG-NH2 can reach 99.51 percent or above, the purity of the mPEG-18beta-GA can reach 99.65 percent or above, the yield of the mPEG-GA and the CUR compound can reach 83.31 percent or above, and the purity of the mPEG-GA and the CUR compound can reach 99.78 percent or above.