Biofouling causes numerous adverse impacts on devices and instruments in a marine environment. The main purpose of the present study is to develop a bioinspired and eco-friendly coating for inhibiting marine biofouling. Herein, based on a bacteriostatic and bactericidal synergistic method, we reported a self-adhesive lubricating copolymer with functional pendant groups, which was synthesized by free radical polymerization using dopamine methacrylamide (DMA), 2-methacryloyloxyethyl phosphorylcholine (MPC), and N-methacryloyloxy benzoisothiazolinone (M-BIT). The copolymer could self-adhere on the steel sheet with a simple dip-coating method and formed an effective antifouling coating on the surface. The adhesion behavior and lubrication property of the copolymer were investigated using X-ray photoelectron spectroscopy and atomic force microscopy. The antibacterial test demonstrated that the copolymer was efficient in inhibiting the accumulation of bacterial biofilm and normal growth of E. coli and S. aureus, and the algae inhibition test revealed that the copolymer had great suppression ability against Chlorella and Nitzschia closterium. Furthermore, the marine field test showed that the copolymer was endowed with excellent antifouling property, which was owing to the bacteriostatic performance of zwitterionic phosphocholine groups in MPC and the bactericidal effect of M-BIT. In conclusion, the bioinspired copolymer can achieve effective marine biofouling prevention by a bactericidal and bacteriostatic synergistic strategy, and it may be used as a self-adhesive coating for achieving surface functionalization of marine devices and instruments.