A composite of multi-scale fiber hybrid system was prepared by mixing polyoxymethylene (POM) fiber and basalt fiber (BF). The basic mechanical properties, including flexural strength, compressive strength, bending toughness and direct tensile strength were investigated. Microscopic analysis was conducted using scanning electron microscopy and digital electron microscopy. The results of flexural and compressive strength tests show that the flexural strength and early compressive strength of the specimens mixed with two types of fibers are significantly better than those mixed with POM fiber alone, and there is a small decrease in the 28 d compressive strength. The three-point bending test shows that POM fiber alone can improve the toughness of cement-based materials and increases the equivalent flexural strength of the material. After mixing with BF, the equivalent flexural strength is further improved. Microscopic analysis shows that POM fiber and BF are tightly combined with the matrix, and the two fibers can act synergistically at the macro and micro scales, to jointly play a crack resistance effect, improving the toughness and strength of cement-based composite materials.