To improve the crack resistance and durability of the cement-stabilized macadam base, different amounts of polypropylene fiber were added to it. First, the optimal polypropylene fiber content was determined by testing the splitting tensile strength of the specimen at different curing ages. Then, the effects of polypropylene fiber incorporation on compressive strength, splitting tensile strength, and flexural tensile strength were analyzed by macroscopic mechanical property tests. Finally, the semicircular bending test was carried out on two groups of specimens, and the digital image correlation (DIC) technique was used to monitor and compare the loading process in the full time domain. In this way, the displacement-time curves of the specimens were obtained. The test results show that the optimal content of polypropylene fiber in the cement-stabilized macadam base is 0.10%, and the incorporation of polypropylene fiber can improve the macroscopic mechanical properties of the cement-stabilized base, delay the development of cracks in the cement-stabilized base, and reduce the strain concentration and displacement surge through stress transmission.