The monodisperse and precipitated silica (SiO
2) were modified by coupling agent Si747 in liquid phase and the SiO
2/natural rubber (NR) composites were prepared by latex compounding technology. The structure and properties of Si747-modified SiO
2/NR composites were characterized by rubber process analyzer, DMA and SEM. The results show that in terms of the vulcanization characteristics, compared with the unmodified SiO
2, the scorch time and the positive vulcanization time of the composites obtained by using coupling agent Si747 modified SiO
2 and NR are shortened, which promoted the vulcanization process of rubber. The scorch time and the positive vulcanization time of the monodisperse SiO
2/NR vulcanizates were longer than that of the precipitated SiO
2/NR vulcanizates before and after SiO
2 modification; Considering the physical and mechanical properties, compared with unmodified SiO
2/NR vulcanizate, the tensile strength of the modified monodisperse SiO
2/NR vulcanizate is increased by 17.4%. The resilience and wear resistance are improved by 9.5% and 32.6%, respectively. The heat-build up is reduced by 24.3%. In terms of dynamic viscoelasticity, the modified monodisperse SiO
2/NR vulcanizate has the lower Payne effect, the better dispersibility of the filler and the weaker filler network compared with the modified precipitated SiO
2/NR vulcanizate. In terms of dynamic mechanical properties, the performance in wet-slip resistance of modified monodisperse SiO
2/NR vulcanizate is slightly lower than that of the modified precipitated SiO
2/NR vulcanizate, but the rolling resistance is much better than the latter and saves more energy.