约束临界问题在平时的习题或高考题中时有出现.本文从教材中的习题入手,以高考试题为载体,根据约束条件限制的个数和约束条件的隐蔽性,将约束临界问题进行了分类,并重点分析了其中的3种类型. Constraint critical problems in the usual problems or college entrance examination questions sometimes appear.This paper starts from the exercises in the textbook to the college entrance examination questions as a carrier, according to the constraints of the number of constraints and the covert conditions of the constraints, the binding of the critical issues are classified , And focus on the analysis of the three types.