Web crawler technology is a technology that automatically obtains Internet information. It simulates human browsing behavior on the Internet through programs, automatically accesses web pages and extracts the required information. Web crawler technology can be used in various application scenarios, such as search engines, data mining, information monitoring, etc. The basic principle is to send a request to the target website through the HTTP protocol, obtain the web page content, and parse the web page structure to extract the required information. The core of web crawler technology is web page parsing and data extraction, which requires the use of various technologies and tools, such as regular expressions, XPath, BeautifulSoup, etc. At the same time, web crawler technology also faces some challenges and limitations, such as anti-crawler mechanisms, website access restrictions, etc. Therefore, when using web crawler technology, you need to comply with relevant laws, regulations and ethics to ensure legal compliance.