from selenium import webdriver
from time import sleep

dr = webdriver.Chrome()

dr.get("http://pj1.cciccloud.cn/portal/website/01/index.html")
time.sleep(3)
dr.find_element_by_xpath("//a[@class='Content_a']/span").click()

驱动Firefox 则可以

 

更新了Chrome的驱动，即可，要和浏览器版本相匹配