I found the problem! 
My ISP China Telecom blocked the OCSP domain ocsp.int-x3.letsencrypt.org
I added the real IP in hosts for OCSP then it worked! 
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I found the problem! 
My ISP China Telecom blocked the OCSP domain ocsp.int-x3.letsencrypt.org
I added the real IP in hosts for OCSP then it worked! 