Plasma electrolytic fluorination (PEF) has emerged as a promising surface treatment technology to improve the properties of metal surfaces by forming a fluorinated layer. This paper investigates the effect of CA as an additive on the plasma electrolytic fluorination process of 6061 aluminum alloy. Different concentrations of CA were added to the electrolyte, and their effects on the discharge characteristics, coating growth, and microstructural evolution were comprehensively investigated. The results indicate that the addition of an appropriate amount of CA leads to a smoother coating surface, reduced friction coefficient and porosity, as well as improved corrosion resistance. In addition, the plasma discharge becomes weaker after adding CA. This modified PEF process using CA offers great potential for engineering applications.