To achieve high quantum efficiency and good stability has been a main direction to develop GaAs photocathode recently. For a molecular beam epitaxy grown, (100) wafer, Be doping and 1 μm thickness reflection-mode GaAs emission layer, a new-type gradient doping structure, in which from GaAs bulk to surface doping concentrations are distributed gradiently from 1×1019 cm-3 to 1×1018 cm-3, was designed. And the new-type GaAs emission layer was prepared into photocathode by (Cs,O) activation technique. The spectral response curves show that compared to common uniform doping GaAs photocathode, the quantum efficiency of gradient doping GaAs photocathode is increased within whole response waveband, with integral sensitivity of 1580 μA/lm, and the photocathode also behaves more stable, which proved that the new-type gradient doping structure is executable and practical, has great potential, and the development of it provides an important approach to development of the national GaAs photocathode with high performance. The inherent reasons why the new-type GaAs photocathode obtained higher quantum efficiency were also discussed.