Multi-needle electrospinning is a simple and general method for mass preparation of nanofiber membranes, which has great industrial potential. However, due to the bending instability produced in the process of electrospinning, the deposition uniformity of the nanofibers has been very worrying, resulting in uneven nanofiber films, which seriously affects the batch application of electrospinning films in environmental filtration, new energy and medical fields. In order to improve the uniformity of nanofiber deposition in multi-needle electrospinning, we propose an auxiliary flow field system (AFF), which can effectively improve the non-uniformity of nanofiber deposition. After image processing of electrospun nanofiber films, we quantified the uniformity of fiber deposition with the index of gray distribution, and verified the effectiveness of this method. Combined with the multi-physical field analysis of the experimental model, the influence mechanism of cross-wind field on the uniformity of fiber deposition was revealed. By optimizing the experimental parameters, the non-uniformity of nanofiber deposition was reduced by 49. 19%.