Concrete usually possesses drawbacks of low flexural strength and prone to crack. In this research, Field's metal with a low melting point was introduced into the cement matrix to improve the crack resistance, thereby enhancing the flexural strength and toughness of cement matrix. A comparative study was conducted to elucidate the effects of the Field's metal on the mechanical behavior, microstructure, capillary permeability, hydration, and electrical properties of cement paste. By tuning the fraction of the Field's metal, the flexural strength and toughness showed the highest increase of 41% and 94%, respectively. The enhancement of flexural properties can be attributed to the filling effect of the low melting metal into the voids in the matrix, bridging effect of metal particles and the higher flexural strength as well as the higher fracture toughness of the metal. This approach opens a new research direction for the design and application of an innovative functional building materials.