In complex group decision-making, decision makers and decision attributes are the core of the relevant activities. Targeting the problem of scheme ranking and behavioural characteristics that exist in group decision-making, from the perspective of group negotiation and decision-making system coordination, by exploiting the grey target and grey relation analysis, this paper establishes a novel grey group decision-making approach. We define a group measure matrix of scheme, consensus ideal scheme, and decision-making resource coefficient. Then, by borrowing Nash's bargaining idea, and maximizing group negotiation satisfaction and minimizing system coordination deviation, we construct a two-step optimization model to solve for the group consensus ideal scheme and its measure value matrix. In addition, we take decision-making schemes as research objects; and from the two dimensions of decision maker and attribute, we characterize and measure the closeness degree of decision maker information and attribute information by using the distance between the group measure matrices of scheme and consensus ideal scheme, so that we are able to construct a novel grey scheme matrix similar incidence analysis model. Lastly, we take the group decision-making problem of selecting the location of a garbage disposal station as a case analysis, and explore the economic significance and theoretical value of the model. (C) 2018 Elsevier B.V. All rights reserved.