In order to clarify the principal vector in the force system simplification is not force, and whether the principal vector and resultant force are the same physical quantity, the article analyzes it from definition, characteristic elements, vector operation criteria, points out that the principal vector in force system simplification is not force, presents out the difference of principal vector and resultant force by using example illustration. The result shows that it can calculate a principle vector with a known force system, but the force system does not always exists the resultant force, providing reference for the teaching and study of the mechanics of the relevant sections.% 为了明确力系简化中的主矢是不是力，主矢与合力是不是同一个物理量，该文从定义、特性要素、矢量运算准则进行了分析，明确指出力系简化的主矢不是力，采用例证的方法阐明主矢与合力的区别，分析表明，总可以计算出一个已知力系的主矢，但该力系不一定存在合力，为力学相关章节的教学和学习提供强有力的保证。
展开▼
