Human health damage and economic losses due to bacterial infections are very serious issues worldwide. Excessive use of antibiotics has caused an increase in bacterial resistance. Fortunately, various non-antibiotic antibacterial materials have been developed to treat bacterial infections without bacterial resistance. This review mainly introduces functional polymers with an intrinsic antibacterial ability and their applications in antibacterial drug delivery systems. The antibacterial strategies of polymer-based coatings include resisting bacterial adhesion and releasing bacterial debris. Their direct and assisted antibacterial effects are also discussed. The development of polymer-based antimicrobial drugs and coatings is prospected in this review.