The invention relates to a complex composed of dasatinib and nonlinearly-structured polyethylene glycol, which is shown in a general formula I, wherein Core represents a core structure of the nonlinearly-structured polyethylene and is selected from hydrogen-removing residues of hydroxyls of pentaerythritol, methyl glucoside, saccharose, diethylene glycol, propylene glycol, glycerin or polyglycerol; P represents polyethylene glycol residues with the number-average molecular weight of 300Dalton to 60000Dalton; X represents a single bond, -CH2CO-, -CH2CH2OCO- or -CH2CH2NHCO-; and i represents 3, 4, 6 or 8. In the complex, the medicine loading rate is greatly increased due to the adoption of the nonlinearly-structured polyethylene glycol. The evaluation result shows that the solubility of the modified dasatinib is improved, the medicine absorbability of the modified dasatinib is enhanced, the inhibition strength of the modified dasatinib to tumor cells is basically superior to that of the dasatinib to the tumor cells, and the modified dasatinib has no obvious toxicity. The structure of the complex provided by the invention is as shown in the specification.