文章提出具有中性域X^*(X^*≠{x})X的上的双枝模糊决策的概念和决策优化分析模型、决策判定定理、决策识别定理、决策去余定理和决策因素域X上的挖洞原理。双枝模糊决策具有下列特征：决策结论的双向依赖特性，决策结论的叠加合成特性，决策结论的枝-分离特性，决策结论的枝-退化特性，决策结论的非失误特性。研究结果得到了应用。

This paper proposes the concept of both-branch fuzzy decision on X, which contains neutral universe(X^*≠{x}), and the optimal decision analysis model. In addition, the paper proposes decision judgement theorem, decision discernment theorem, decision surplusage-discarding theorem and hole-digging principle on decision factors universe X. Both-branch fuzzy decision has such characteristics as decision two-direction dependence character, decision piling-synthesis character, decision branch-separating character, decision branch-degeneration character, and decision non-fault character. The research results have found application.