At 8.25pm on Friday (24) crews were called to a fire at the former RAF Upwood site.
Crews from Ramsey, Huntingdon, Stanground and Chatteris attended the incident.
Firefighters arrived to find a well-developed fire involving three derelict buildings. Wearing breathing apparatus they extinguished the fire using hose reels and jets before returning to their stations by 11.15pm.
The cause of the fire was deliberate. Anyone with information should contact police by visiting www.cambs.police.uk to submit an online report or call Crimestoppers on 0800 555111.