针对传统投影算子无法解决投影相同时二元语义排序问题,定义了在二元语义信息下,方案与正负理想点形成向量,提出了基于正、负理想点的双向投影贴近度计算公式;并研究了属性权重已知条件下双向投影贴近度的测算,最后以具体的算例说明了方法的有效性和可行性. Aiming at the problem that the traditional projection operator can not solve the binary semantic ordering problem when the projection is the same, the formation vector of the scheme and the positive and negative ideal points is defined under the binary semantic information, and the bidirectional projection closeness formula based on positive and negative ideal points is proposed. And the closeness of two-way projection under the known condition of attribute weight is studied. Finally, a concrete example is given to illustrate the effectiveness and feasibility of the method.