Abstract: The widespread application of ordinary concrete in high-toughness engineering is limited by its low tensile strength, high brittleness, and propensity for cracking. Although short-cut carbon fibers can significantly enhance its mechanical properties, systematic research on mix proportion optimization and the dynamic impact resistance mechanism remains lacking. In this study, sodium polyacrylate (PAAS) was used as a dispersant. Combining image analysis with nearest-neighbor distance statistics, we quantitatively evaluated the dispersion uniformity of carbon fibers, determining the optimal PAAS dosage to be 8% of the carbon fiber mass. Based on this, the water-to-binder ratio was optimized. Systematically investigating the initial crack impact count ( N_1 ) and final failure impact count ( N_2 ) of concrete with 0~2% (by volume) carbon fiber content and under different failure probabilities, we utilized the two-parameter Weibull distribution. The results indicate that the Weibull model accurately describes the probabilistic characteristics of the impact resistance of carbon fiber-reinforced concrete. When the fiber content is below 1.4%, both N₁ and N₂ increase significantly with higher fiber content. The enhancement rate ( \delta _r ) of the initial crack impact resistance exhibits the most significant increase within the 0.8%~1.1% fiber content range. At 1.4% fiber content, the enhancement rate ( \delta _r ) increased by 160%. Beyond 1.4%, the reinforcing effect tends to saturate or even decrease. The proposed synergistic design methodology focusing on dispersion uniformity–fiber content–toughness' provides a theoretical basis and practical reference for the engineering application of short-cut carbon fiber-reinforced concrete.