The Cyanobacteria was catalytically pyrolyzed in methanol atmosphere using magnesium-aluminum layered double oxide/ZSM-5 composites (MgAl-LDO/ZSM-5) as a catalyst. The largest liquid yield of 67.68% was obtained in methanol atmosphere, which was much higher than that obtained without methanol under same reaction condition. The Gas chromatography-Mass spectrometer data proved that the organics phase contained less O-compounds and N-compounds and more aromatic compounds. And the ultimate analysis results showed that this bio-oil had much higher HHV values and lower O/C molar ratio. The co-processing methanol atmosphere and bifunctional catalyst would be a promising means for improving the quality of bio-oil.