The formation of carbon fiber reinforced plastic (CFRP) fatigue damage is complicated, and fatigue damage continues to expand over time and as the load increases. Focusing on the problems associated with existing probability-based diagnostic imaging methods, i.e., high misjudgment rate of damage location, low damage imaging clarity, and poor visualization effect, this paper proposes a CFRP fatigue damage-probability diagnostic imaging method based on a time-of-flight (ToF) damage factor. The method uses a new damage factor to improve existing probability-based diagnostic imaging methods, and studies the fatigue damage of CFRP plates under different fatigue loading cycles. Experimental results demonstrate that, compared with existing methods, the damage location error of the method is reduced by at least 49.85%, which provides a new method for the accurate quantitative analysis of CFRP fatigue damage.