Permutation and combination are the essential knowledge in such subjects as probability theory,statistics and economic management.Based on the theoretical difficulties of studying,researching and applying permutation and combination,corresponding breakthrough methods are induced：Judging whether the problem is on permutation or combination,it is the key to look at whether the object is related to the sequence or not;Judging whether the addition principle or the multiplication principle is applied,and it is crucial to look at whether it is a successive or optional problem.Meanwhile,the basic types and their analysis related to permutation and combination problems are analyzed.These are done to provide some understanding and ways to explore for economic management,statistic research and the study of probability theory.