apparatus may include a first solution infusion set 301 a first solution infusion pipe 303 a second solution infusion set 302 and a second solution infusion pipe 304 the first solution infusion set 301 communicates with the inner drum 201 by means of the first solution infusion pipe 303 the second solution infusion set 302 communicates with the outer drum 202 by means of the second solution infusion pipe 304 in this embodiment the fiber collecting apparatus may include collection plates 7 distributed around the peripheral part of the solution spraying apparatus and the supporting base 8 for supporting the collection plates 7 preferably the collection plates 7 may be cylindrical the supporting base 8 is provided with several sliding grooves the cylindrical collection plates 7 are mounted in the various sliding grooves to realize regulation of relative distances of the cylindrical collection plates 7 away from the outer drum 202 furthermore the collection plates 7 are grounded as negative electrodes the cylindrical collection plates 7 are perpendicular to the sealing plate 207 or the isolation plate 2 preferably the relative distances of the surfaces of the cylindrical collection plates 7 away from the tail ends of the pipe tail portion 206 are greater than 10 mm additionally the fiber collecting apparatus may also be multiple battens arranged perpendicularly to the sealing.