Aiming at the problem of risky large group decision-marking and considering the complexity of experts' weights determination, a large-group decision-making approach based on the cumulative prospect theory and two-lawyer expert weight determination is proposed. The 2-tuple linguistic representation model is used to capture and express the evaluation information of experts. The comprehensive prospect value matrix for alternatives is calculated by using the cumulative prospect theory. A two-lawyer expert weight determination method is proposed. Value vectors of experts are classified by using the clustering method and clusters' weights are confirmed by using the clustering result at the first lawyer. The experts' entropy weights are obtained by using the entropy weight method at the second lawyer. The final experts' weights are got by combining the clusters' weights and the experts' entropy weights. The final decision result is obtained by considering the experts' weights and the comprehensive prospect value matrix. Finally, a practical example is provided to illustrate the effectiveness and feasibility of the proposed approach.