Surface fogging causes various inconvenience for human daily life, especially for clinic inspection and medical diagnosis, hence the surfaces with reliable antifogging performances have received tremendous interests. Herein, through a facile adsorption-cross-linking strategy, a dual functional coating with both excellent antifogging/frost-resisting properties and reliable antibacterial activity has been steadily integrated onto varied substrates. A series of copolymers poly(HEAA-co-QAC-co-BP) with UV-initiable BP groups are synthesized, and then are covalently fixed on the substrate surfaces via UV triggered cross-linking reaction. The hydrophilic HEAA units endow the surface with excellent antifogging performance, while the introduced QAC groups bring essential antibacterial activity. ZOI results prove that the antibacterial activity stems from the surface contact-killing of bacteria, without releasing any bactericidal agents. Moreover, the functional surface exhibits remarkable resistance toward non-specific protein adsorption as well as no obvious effect on the hemolysis. The coating with the unique merits of both antifogging and antibacterial properties could find broad applications in antifogging fields, in particular for medical diagnosis, health monitoring, etc.