固步自封
[词典] continue walking in the old steps and seclude oneself; be a standpatter and be proud of it; be self-satisfied with being a stick-in-the-mud; rest complacently on one's laurels;
[例句]我们不能固步自封，夜郎自大，有了一点成绩就沾沾自喜。
We shouldn't feel conceited and self-satisfied and rest on our laurels because of some success.