The ultra-high toughness cementitious composites (UHTCC) was modified by different types of epoxy emulsion, the effect of the emulsion on working performance, mechanical properties and impermeability of UHTCC were studied. The result showed that compared with the control without epoxy emulsion, the type I and type II epoxy emulsion improved the working performance of UHTCC with low dosage. However, the type III epoxy emulsion exhibited an improvement effect on working performance of UHTCC only when the dosage was high. The addition of epoxy emulsion to UHTCC caused a decrease in compressive strength and flexural strength, but epoxy emulsion and hydration products formed an excellent energy absorption mechanism in the specimen and enhanced the elastic modulus of UHTCC. Type I and II epoxy emulsion had little effect on the tensile properties of UHTCC. Type III epoxy emulsion greatly increased the ultimate tensile strength of UHTCC, and the strain hardening phenomenon disappeared at low dosage level, however, the effect of strain hardening had been improved by increasing its dosage.