The utility model discloses a nuclear power diesel engine starts air compressor machine unit, the 2nd compression host pass through second coupling joint second motor, and a compression host is through the first motor of first coupling joint, a compression host, the 2nd compression host give vent to anger the end through the pipe connection to leading filter, leading filter passes through pipe connection refrigeration dryer's air inlet, pipe connection post -filter is passed through to refrigeration dryer's gas outlet, post -filter is through the give vent to anger metal collapsible tube of usefulness of pipe connection. The utility model discloses an air compressor machine unit has adopted one division one design that is equipped with, and all spare part integration are on at the bottom of one, even the due effect of whole nuclear power generator in -process still can be accomplished to whole one -tenth sled under the circumstances when one of them compression host damages or maintains, this security that has increased entire system widely can both start diesel generator by carrier gas at any unexpected in -process promptly.