In accordance with one working day or a doffing period of spinning machine, sub-calculates operating periods and non-operating periods of the exhaust system in viscose filament workshop, then obtains average values of the periods to determine the air supply volum to the workshop. The supply air volum is 58.1 % to 65.8 % of the former design. Meanwhile by means of applying the air curtain for spinning machine, improving the air-conditioning ventilation system of workshop and replacing the traditional air-conditioning model with "machine-focused and workshop subsidiary" model technology, saves the energy consumption of air-conditioning by 25 % to 69 %.