Abstract: This is an article in the field of ceramics and composites. In this article, the effects of IOT and polyvinyl alcohol (PVA) fiber (PF) on the compressive strength, four-point flexural strength, flexural toughness, pore structure of cement-based composites were studied and discussed in detail. The conversion relationship between compressive strength and four-point flexural strength was established. The results showed that the incorporation of IOT had an enhanced effect on the mechanical properties, and this enhanced effect showed a trend of first increasing and then decreasing with the increase in the substitution rate of IOT. However, when PF was added, the mechanical properties under the combined effect of PF and IOT were further improved and showed good toughness. In addition, the internal pores of the matrix with IOT substitution rate of 40% and PF were obviously reduced. Thus, it was concluded that the cement-based composite material had good mechanical properties when the 40% IOT was combined with PF.