In order to solve the multi-attribute group decision-making problem in complex decision-making environment, a three parameter interval grey number decision-making method based on similarity was proposed considering the grey number characteristics of the problem and the psychological factors of the decision-makers. Firstly, from the point of view of interval length and center of gravity, the similarity calculation formula was proposed. Secondly, considering the relationship between the decision-maker and the environment, the decision-maker's psychological cognitive field based on similarity was established, and the data potential theory was introduced to obtain the decision-maker's weight. Combining distance formula and entropy weight method, the attribute weight was obtained. Finally, a scheme decision-making model based on the combination of prospect theory, similarity and the technique for order preference by similarity to ideal solution (TOPSIS) was constructed. An example was used to prove that the model has the effect of difference between optimization schemes, and the operability and rationality were verified.