The controversy over the concept of legal validity lies in the definition of “law” and “validity”. But in its essence，the core connotation of legal validity is still the binding force of legal norms within the effective scope. The concept of legal validity should be re-examined through the two topics of “rank of legal validity” and “legal efficacy”，and the understanding of legal validity is based on the two dimensions of “correctness” and “authority”. In terms of content，it should be noted that social validity and moral validity have a profound impact on legal validity. In practice，it should be noted that legal validity，legal efficacy and legal existence have a certain tendency to merge concepts. These understandings help us to understand the concept of legal validity more accurately and deeply，but they cannot completely eliminate some conceptual ambiguities.