The invention discloses a dynamic key quantitative negotiation method based on wireless physical layer channel characteristics, and solves the problems of low key generation rate and low entropy of the present quantitative negotiation method. The quantitative negotiation process comprises the steps that both data communication sides acquire communication data information in advance, key quantitative negotiation parameters are initialized, one communication side performs dynamic grouping slope quantization on each segment of data in turn after segmentation to obtain an initial key, both data communication sides perform key negotiation on the initial key according to grouping subscript record arrays and abandon arrays, and finally both sides obtain the final key. The key flow generation rate can be enhanced, and 128-256bit of key flow can be generated within the duration of about 200 seconds. High key flow entropy can be guaranteed so as to be better than the up and down interval quantization algorithm and the fixed grouping slope quantization algorithm. The method is applied to key generation negotiation in wireless network encryption communication so as to realize secure communication.