Nanomaterials have brought an unprecedented revolution to the development of building materials with their unique properties of light, electricity, heat and magnetism. According to the future development trend of building materials and the development and application prospects of nanomaterials, this paper studies the application of nanomaterials in new building materials, providing a better development space for the future direction of new building materials. This research mainly conducted research from five aspects: the effect of modified carbon nanotubes on the bending performance and compressive strength of cement-based materials; the effect of composite materials on the effectiveness of cement-based materials in electromagnetic wave protection; the effectiveness of nano-carbon fiber cement materials Self-shrinking; Formaldehyde gas sensitivity of nanomaterials; The effect of surface modification of nano-TiO2 on the thermal stability of wheat straw fibers. The test results show that the results of improving the mechanical properties include: compressive strength increased by 132%, tensile strength increased by 34.28%, and flexural strength increased by 124.85%. When the silica fume content is 0, the electromagnetic shielding efficiency of different doped carbon nanometers are 22.1, 25.8, 27.6 and 31.4 respectively. As the silica fume content gradually increases, the ability to shield electromagnetic waves is stronger. When the water-cement ratio is 0.25 and 0.3, the autogenous shrinkage value of the nano-carbon fiber cement paste specimens shows a trend of first decreasing and then increasing. The optimal operating temperature of formaldehyde gas sensor is 250℃, and 2% is the optimal doping concentration of In2O3. In the range of 0-2% nano-TiO2 addition, the content of surface-modified nano-TiO2 particles has little effect on the thermal stability of wheat straw fibers.