A new method to synthesize high-purity Ti3AlC2 bulk material by hot-pressing was presented through adding a little amount of B2O3 as a low-temperature aid. The elemental Ti, Al, and active carbon powders were used as raw materials with a molar ratio of 3:1.2:2.The effect of sintering temperature on the purity of Ti3AlC2 was investigated at the range of 1200°C to 1500°C. XRD and SEM were used to characterize the product synthesized. High-purity Ti3AlC2 bulk materials, in which almost no TiC phase could be found, were synthesized by hot-pressing at 1400°C and 1500°C for 1h in flow Ar atmosphere. The roles of B2O3 addition were considered as weakening the thermal explosive reaction in the mixture of elemental Ti, Al, and active carbon and increasing the purity of Ti3AlC2 in addition.