The article discusses the possibilities and approaches to the use of visual analytics meth-ods to reduce the dimension of decision-making problems. The main directions of reducing the dimension of the decision-making problem, as well as increasing its information content using three-dimensional visualization methods are highlighted: filtering alternatives, group-ing and ranking criteria. The application of several methods of visualization of choice set and criteria set are considered: histograms with grouping by alternatives, histograms with group-ing by criteria, correlation surfaces of criteria. The advantages and disadvantages of visualiza-tion methods are highlighted in relation to solving the problem of reducing the dimension of choice set and criteria set. The basic principles of increasing the efficiency of visual analytics of three-dimensional images for decision-making problem in order to reduce its dimension are noted. A description of an experiment on visual analytics of three-dimensional images is given on the example of the problem of choosing an optimal solver OpenFOAM (out of three alternatives) based on 24 results of computational experiments of supersonic flow around a cone with different initial parameters. It is noted that with the help of visual analytics, it was possible to find an error in one of the computational experiments, to reduce the number of alternatives to two, and the number of criteria to five, which made it possible to apply tradi-tional decision-making methods to this problem and choose the optimal solver. © 2020 National Research Nuclear University.