The conventional oil well cement stone is a hard and brittle material. Rubber particles have been extensively utilized to enhance the toughness of cement stone；however，the rubber is less compatible with the cement slurry and is easy to float，which restricts its effectiveness in the application. In this study，the micro-nanoparticle composite technology was used to prepare core-shell rubber composite particles by using rubber particles as cores and coating nano-silica on their surfaces. The effects of the obtained rubber composite particles on the properties of cement paste and the mechanical properties of cement stone were investigated. The results showed that four types of core-shell rubber composite particles were successfully prepared by micro-nano particle composite technology，and the most significant toughening effect was observed in styrene butadiene rubber （SBR） composite particles，and it had less effect on the flow properties of cement paste. It was found that the elastic modulus of cement gradually decreased with the increase of the coating amount of SBR composite particles，while the compressive strength showed an increasing trend，which indicated that the loss of compressive strength of cement due to the incorporation of rubber particles could be effectively compensated by increasing the coating amount of nano-silica. Further investigation revealed that when the coating amount of nano-silica was 5%，the optimal addition amount of SBR composite particles in cement slurry was 4%（BWOC），the elastic modulus of cement stone was 6.5 GPa. Compared with the cement stone without SBR composite particles，the elastic modulus decreased by 36.9% ，and the compressive strength was 30.8 MPa，increased by 38.1% ，indicating a significant toughening effect.