The effect of water toughening treatment on mechanical properties of high manganese steel bonded TiC hard alloy was systemically investigated, and the microstructure and element distribution of the alloy before and after the treatment were also evaluated by SEM and EDS in order to understand the internal relationship of its properties. The bending strength and impact toughness of high manganese steel bonded TiC hard alloy by normal vacuum sintering were raised by 154.6% and 125.3%. They were 61.81%, 45.38% and 65.59%, 32.90% for low pressure sintering and vacuum sintering plus low pressure sintering specimen, respectively. The results revealed that water toughening treatment could effectively improve the alloy's bending strength and impact toughness.