An antiferroelectric cathode material, lanthanum-doped lead zirconate stannate titanate （PLZST） located in the vicinity of antiferro-ferroelectric phase boundary, was prepared by solid state calcination method. The electron emission property of the novel antiferroelectric cathode under the negative triggering voltage pulses was investigated. The emission threshold value voltage from PLZST with 0.5 mm width under negative triggering pulses was 500 V. For negative triggering voltage of 500 V and extraction voltage of 3.5 kV, a large emission current of 690 A was obtained. It was indicated that the emission threshold value voltage was low and the emission current was large. Even when the triggering voltage was lower than the positive switch electric field, strong emission current can be obtained from PLZST. Finally, the mechanism of electron emission of PLZST under negative triggering pulses was discussed.