In this paper, hyperbranched PDOPA polyester with precise structure was synthesized by thermal polycondensation. PDOPA showed good solubility, degradability, and biocompatibility. Functional polymers based on PDOPA were prepared by reactions of amine groups in PDOPA with pyrenecarboxylic acid and polylactide, respectively. Wide applications of the PDOPA polyester are expected after modified with functional groups.