The air handling unit of the marine modular air conditioning system boasts powerful combined functions. It can provide mixing, filtration, cooling, heating, humidification, dehumidification, noise reduction, air supply, flow equalization and other functions according to customer requirements, with strong applicability. It is equipped with complete protection functions, including high pressure, low pressure, water cut-off, anti-freezing, safety valve, overload, phase reversal, phase loss, phase balance and other safety protection features. Adopting unique anti-corrosion technology, it can adapt to various marine corrosive environments and operate normally under irregular conditions such as vibration, jolting and swaying.