@song19891121 Have you tried using a Mirror CDN?
e.g. Add this to the custom header block in the ACP:<link href='http://fonts.useso.com/css?family=Open+Sans:300,400,600&subset=latin,latin-ext' rel='stylesheet'>
Edit: You'd probably still get the error nonetheless, but at least the fonts will work? So maybe use this in conjunction with @a_5mith's suggestion.