Polyhydroxyalkanoates (PHAs), recognized as a medical biomaterial, have been proven to promote cell proliferation and tissue repair. PHA has a variety of forms: PHB, PHV, PHHx, and PHBHHx, etc. In this study, PHBHHx was selected as the precursor to fabricate biopolyester films. Specifically, a novel type of biopolyester film was generated through an ammonolysis cross-linking reaction in conjunction with polyamidoamine dendrimer G2.0 (PAMAM). The properties of the resultant biopolyester films were comprehensively evaluated, encompassing surface characteristics, amino group content, and water contact angle. The drug-loading properties and compatibility with osteoblasts of the biopolyester films were also determined. The findings revealed that following aminolysis, the biopolyester film surface exhibited enhanced roughness and an enlarged surface area. Moreover, as the aminolysis duration extended, the hydrophilicity and drug-loading efficiency were significantly augmented. Post-aminolysis, the PHBHHx membrane exhibited a more favorable environment for the adhesion and proliferation of osteoblasts. Overall, the biopolyester film developed in this study provides novel insights and materials for tissue engineering, especially bone tissue repair.