Using three-point loading test method, the flexural strength and flexural elastic modulus of concrete were tested, and the influence of nano-CaCO3 and PVA fibers on the flexural strength and flexural elastic modulus of concrete was explored. The research results show that adding PVA fiber to nano-CaCO3 concrete can significantly improve the flexural strength of concrete. Within the range of PVA fiber content tested in this study, with the increase of PVA fiber content, the flexural strength and flexural elastic modulus of concrete both increase first and then decrease. When PVA fiber content is 0.05%, the flexural strength and flexural elastic modulus reach the maximum value. When an appropriate amount of nano-CaCO3 (<3%) is added into concrete, with the increase of nano-CaCO3 content, the flexural strength and flexural elastic modulus of concrete gradually increase. When the nano-CaCO3 content exceeds 3%, with the increase of nano-CaCO3 content, the flexural strength and flexural elastic modulus gradually decrease.