A new organosilicon‐based polyurea/DOCIT composite coating with excellent mechanical, self‐healing characteristics has been successfully prepared in this paper. The optimal ratio of the two isocyanates has been explored to acquire the highest mechanical strength with 8.56 MPa and best tensile properties with 763%. The breaking strength and elongation remain 3.50 MPa and 915% with 1% antimicrobial agent DOCIT. The self‐healing characteristic comes from dense hydrogen and dynamic disulfide bonds between molecule chains. The composite coating exhibited ideal bacterial resistances for 98.02% and 96.75% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively. The adhesion of chlorella was significantly reduced by approximately 86.48%. This work provides a promising avenue for the development of high‐performance silicone polyurea coatings for marine anti‐biofouling.