High-defense CDN nodes can share the load of the origin server by distributing user requests to different nodes to balance the traffic load, reduce the pressure on the origin server, and improve the performance and stability of the website. Choosing a high-quality, high-defense CDN provider is the key to ensuring the security, performance, and stability of your website. Here are some key points for choosing a high-quality, high-defense CDN:

　　1. Performance: When choosing a high-defense CDN, performance is the key factor. Consider the provider's network infrastructure, server distribution, global node coverage, etc. A stable, low-latency network provides faster loading speeds.

　　2. High defense capability: A high defense CDN should be able to effectively resist DDoS attacks and protect your website from malicious traffic. Understand the provider's DDoS protection capabilities, attack detection and response mechanisms.

　　3. Security: Ensure the provider provides appropriate security measures, including data encryption, SSL/TLS support, and preventing the spread of malicious content.

　　4. Function: Check whether the provider provides the required functions, such as caching strategy, load balancing, HTTPS support, real-time monitoring and analysis, etc.

　　5. Scalability: Ensure that the CDN provider has the ability to elastically expand to increase resources when needed to meet traffic demand.

　　6. Support and service: Find out whether the provider offers 24/7 technical support, as well as their troubleshooting and emergency response capabilities.

　　7. Price: Consider the price of a CDN, but not just the cost, but also the value in terms of performance, features, and support. Don’t just look at price and ignore other key elements.

　　8. Reviews and word-of-mouth: Check the provider's user reviews, customer cases, and user reviews to learn about other customers' experiences and feedback.

　　9. Compatibility: Make sure the CDN is compatible with your website and applications and will not introduce compatibility issues.

　　10. Comprehensive CDN solutions: Some high-defense CDN providers may also provide comprehensive solutions related to security, load balancing, DNS resolution, etc., which can better integrate and manage your cloud infrastructure.

　　The best thing to do is to do adequate research, compare multiple providers, and make an informed choice based on your website needs and budget. Choosing a reliable high-defense CDN provider can significantly improve your website performance and security.