The invention provides an analysis method and device of abnormal data. The analysis method comprises the following steps: record information which indicates a caused 404 fault can be obtained from a website operation log; when a target URL (Uniform Resource Locator) in the record information is an enterprise URL, on the basis of a first preset rule, the enterprise URL is judged; when the target URL in the record information is a product URL, on the basis of a second preset rule, the product URL is judged to realize the judgment of the product URL and the enterprise URL so as to realize a purpose that the enterprise URL and the product URL are independently judged through different preset rules; and when a judgment result shows that the 404 fault caused by the enterprise URL or the product URL is caused by a corresponding search engine, the enterprise URL or the product URL which causes the 404 fault can be indicated to delete, the 404 fault can be prevented from being caused again when the URLs are used, so that website stability is improved, and a probability that the search engine is recorded by a user is increased under a situation that the website stability is improved so as to improve the recording rate of the search engine.