The invention relates to a microalgae culture and wood fiber waste fermentation coupling system and belongs to a biological resource comprehensive utilization technique. The system comprises a microalgae culture unit, a wood fiber waste dry-type anaerobic fermentation unit and an aerobic composting unit, wherein a waste gas delivery pipeline A with a valve C and a biogas residue delivery pipeline with a valve D and a biogas residue conveyor are respectively communicated with the aerobic composting unit and the wood fiber waste dry-type anaerobic fermentation unit, a waste gas delivery pipeline B with a valve A and a biogas slurry delivery pipeline with a valve B and a biogas slurry conveyor are respectively communicated with the wood fiber waste dry-type anaerobic fermentation unit and the microalgae culture unit, a biogas output pipeline with a valve E is installed on the wood fiber waste dry-type anaerobic fermentation unit, and a biogas delivery pipeline, a valve F, a biogas combustion heat exchanger and a carbon dioxide gas and heat delivery pipeline communicate the biogas output pipeline with the waste gas delivery pipeline B. The system has the advantages of good operating effect, low operating cost and no environmental pollution.