Abstract: Layered double hydroxide (LDH) precursors with different metal elements were prepared by co-precipitation method at constant pH value; highly dispersed Cu/Al/Zn, Cu/Al/Ni and Cu/Al/Ni/Zn mixed metal oxygen carriers were obtained by calculation of the corresponding precursors. These oxygen carriers were characterized by XRD, XRF, H₂-TPR, SEM and nitrogen adsorption and their activity in the chemical looping gasification (CLG) of biomass was investigated in a fixed bed reactor. The results indicated that typical hydrotalcite structure appears in the three precursors with stable layer board. The interlayer spacing of Cu/Al/Zn precursor is 0.2642nm, larger than that of the Cu/Al/Ni precursor. The oxygen carriers derived from the corresponding precursors display similar elements contents as the preparation reagents. Due to the synergy among various metals, the Cu/Al/Ni/Zn oxygen carrier shows the highest reaction activity and anti-sintering ability. The addition of Ni and Zn has a positive effect on the activity of CuO and reduce its reduction temperature; Zn shows a better synergistic effect than Ni with Cu. The carbon conversion reaches 82.03% for the CLG of biomass with Cu/Al/Ni/Zn as oxygen carrier; the surface area of Cu/Al/Ni/Zn remanis 5.995m²/g after the CLG reaction, suggesting that it could be an ideal candidate for the CLG of biomass.