Graphitic carbon nitride (g-C₃N₄) is a carbon-based conjugated polymer material with a crystal structure similar to graphite, which exhibits unique potential in the field of photocatalytic antibacterial activity. However, factors such as easy recombination of photogenerated electron(e^-)-hole(h⁺) pairs, incomplete sunlight absorption, small specific surface area, and poor adsorption properties of g-C₃N₄ photocatalysts leaded to low photocatalytic efficiency, limiting their antibacterial effectiveness. To overcome these problems, strategies such as morphology control, precious metal deposition, element doping, and heterostructure construction were employed to functionalize g-C₃N₄ and fully activated its antibacterial potential. A detailed introduction was given to the optimization strategies for the photocatalytic antibacterial performance of g-C₃N₄, with a focus on the current state of research on its photocatalytic antibacterial properties in water disinfection, antibacterial dressings, antibacterial textiles, and food packaging. The challenges currently faced in the development of g-C₃N₄ photocatalytic antibacterial agents were highlighted. In order to address the increasingly severe challenge of microbial contamination, future research directions are suggested: 1) deepening the research on the mechanisms of reactive oxygen species (ROS) induced damage to bacterial cell membranes, intracellular proteins, DNA, et al; 2) exploring the antibacterial applications of g-C₃N₄ on broad-spectrum bacteria such as drug-resistant bacteria and commonly used fungi; 3) enhancing the adaptability of g-C₃N₄ in different environments.