Polypropylene (PP) scaffolds are the most commonly used biomedical scaffolds despite their disadvantages, which include problems with adhesion, infection, and inflammatory responses. Here, we report on the successful development of a facile one-step method to fabricate a series of novel triclosan polydopamine polypropylene (TPP) composite scaffolds and thereby effectively improve the biocompatibility and long-term antibacterial properties of PP scaffolds. The antibacterial triclosan can effectively interact with dopamine during biocompatible polydopamine formation on the PP scaffold by one-step green fabrication. Thanks to the sustained release of triclosan from the biocompatible polydopamine coating, a 5 mm × 5 mm sample of TPP-coated scaffold made with a triclosan concentration of 8 mg∙mL−1 (referred to herein as TPP-8) exhibited a continuous antibacterial effect against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) for more than 15 d, at maximum antibacterial volumes of 2 and 5 mL, respectively. Our study establishes a new direction for facile long-term antibacterial studies for medical applications.