The invention relates to an ASGPR protein target therapy agent and application and belongs to the technical field of novel nano target therapy preparations. The therapy agent is formed by self assembly of a block polymer, and two blocks of the block polymer are a perylene diimide polymer chain segment and a glycopolymer chain segment respectively. The therapy agent can realize photoacoustic imaging and photothermal therapy on Hep G2 tumor. The therapy agent combines excellent optical properties of perylene diimide which can be used for photoacoustic imaging-medicated photothermal therapy withthe advantages of water solubility and specificity combination with the Hep G2 tumor of the glycopolymer. The invention has the advantages that operation is simple, and the obtained therapy agent is easy to prepare and has efficient treatment effect in cancer treatment.