Aims: To improve the comprehensive performances of a one-part room temperature vulcanized silicone rubber (RTV-1 SiR), Nano-SiO2 particles are employed as the reinforcing agent. Materials and methods: The SiO2/RTV-1 SiR composite is prepared using PDMS, ND42, D-60 and HMDS-modified SiO2 particles by mixing method. And then, the mechanical and electrical properties, including shear strength, tensile strength, hardness Shore A and volume resistivity, are investigated using experimental method. Results: The addition of nano-SiO2 particles can improve the properties of the SiO2/RTV-1 SiR composite in different degrees. And, the incorporation of 25 similar to 30 phr nano-SiO2 particles is found to be reasonable for silicone rubber composite with the best comprehensive performances. Conclusions: The significant improvement of mechanical properties and electrical insulation of SiO2 may be contributed to the addition of modified nano-SiO2 particles. Additionally, the excellent comprehensive performances of SiO2/RTV-1 SiR composite guarantee a potential applications as electrical-insulating adhesives.