The effects of nano SiO2 mass fraction, steel fiber volume fraction, notch depth on fracture parameters and load deflection curves of the nano SiO2 and steel fiber reinforced concrete specimens were investigated and analyzed through the three point bending test. The results indicate that the addition of nano SiO2 and steel fiber can improve the fracture toughness of the specimens with the appropriate fraction. When nano SiO2 mass fraction is less than 5%, the fracture toughness is increased gradually with the increase of nano SiO2 mass fraction. While, the fracture toughness begins to decrease with the increase of nano SiO2 mass fraction after nano SiO2 mass fraction exceeds 5%. With the increase of steel fiber volume fraction, the fracture toughness is increased. The fracture toughness of the specimens decreases with the increase of the notch depth.