The invention provides a no-clean air filtration device and a new and old filter screen replacement method thereof and belongs to the fresh air ventilation air handling technical field. The no-clean air filtration device comprises a box and a filter screen and also comprises a rotary shaft, a motor and a tray; the box comprises a lower portion front baffle, a lower portion rear baffle, the front air inlet, the rear air outlet, an upper front groove plate, an upper rear groove plate and side plates; two ends of the rotary shaft are arranged on the lower portions of the side plates in a rotating mode; the motor is arranged outside the side plate which is arranged on one side; the motor is fixedly connected with the left end of the rotary shaft; the tray is arranged at the lower position inside the upper front groove plate and the upper rear groove plate; the filter screen comprises a filter screen laminating layer, a filter screen working layer and a fouling screen winding drum; the filter screen laminating layer is arranged above the tray; the filter screen working layer is vertically arranged on one side of the front air inlet; the fouling screen winding drum is arranged on the rotary shaft in a sleeving mode. The total using time of the no-clean air filtration device is 2 to 20 years. According to the new and old filter screen replacement method, the replacement can be performed manually or the filter screen can be matched with an intelligent control module which is arranged on a no-clean total heat fresh air ventilator for use. According to the no-clean air filtration device and the new and old filter screen replacement method thereof, the manpower and material resources are saved and sales are expanded.