Due to the large shrinkage deformation and high cost of high ductility fiber reinforced cementitious composites (HDCC), domestic materials such as PVA fibers and fly ash have been used to prepare HDCC with low shrinkage and low-cost. In this study, the micro and macro experiments on HDCC were conducted and analyzed. It is shown that the hydration reaction of HDCC is delayed with the increase of fly ash content, resulting in a decrease in the mechanical properties and a variation in the interface micro mechanical parameters of the fiber matrix. This promotes the extraction of fibers from the matrix, significantly improves the ductility and toughness, and reduces the shrinkage deformation.