在google管理员工具中，有一个Site configuration中有个设置Settings,通过这个设置，可以改变google蜘 蛛对网站爬行的频率。在Crawl rate中，有两个选项，一个为Let Google determine my crawl rate (recommended)让谷歌决定爬行频率，另一个即是自主设置的蜘蛛爬行频率,如下图：
通过修改第二个，可以达到让蜘 蛛常来爬行网站的频率，如果你的站很大，建议不要修改很大值，不然会加大服务器的负担，影响网站的运行。
谷歌建议：We recommend that you set a custom crawl rate only if you're experiencing traffic problems with your server（当您遇到服务器遇到问题的时候我们建议您设置自定义抓取率).
速度条有两个提示：
1.Slower
May reduce freshness and number of crawled pages
2.Faster
May increase Googlebot traffic on your server
爬行频率具体可以根据自己网站的实际情况来调整。
设置完成之后，会收到一封google管理员的来信，信的内容如下：
We've received a request from a site owner to change the rate at which Googlebot crawls this site: http://www.goodtoday.com.cn/
New crawl rate: Custom rate
- 0.0060 requests per second
- 160.244 seconds per request
Your request will take a day or two to come into effect.
This new crawl rate will stay in effect for 90 days.
We recommend that you set a custom crawl rate only if you're experiencing traffic problems with your server. To use Google's recommended crawl rate, follow these steps.
1. On the Dashboard, select the site you want.
2. Click Settings.
3. In the Crawl rate section, select "Let Google determine my crawl rate".
需要特别指出的是，你的请求将在一到两天产生影响（作用），新的爬行频率将会持续90天。
