While I think you mixed up the expected and actual result, I can confirm that https://example.com?a=中文#b=中文 is displayed as https://example.com/?a=中文#b=%E4%B8%AD%E6%96%87 in Chrome 63 and Canary.
Firefox and Safari display the URI as https://example.com?a=中文#b=中文

Bisect info: 507466 (good) - 507488 (bad)
https://chromium.googlesource.com/chromium/src/+log/8a6beb7a..0d40e427?pretty=fuller
Suspecting r507481 = f8f6ed59949be4451ee2f5443d8a313f102fde60 = https://crrev.com/c/668363 by mkwst@chromium.org
"Percent-encode UTF8 characters in URL fragment identifiers."
Landed in 63.0.3237.0

The commit message says "This brings us into line with Firefox, Safari, and the spec", 
but I see #b=中文 in Firefox 52-59, which is obviously user-friendly.
The new behavior in Chrome is not friendly to non-English users.

After looking into what's causing this, it feels like this should also happen on other platforms. https://chromium-review.googlesource.com/c/chromium/src/+/828733

As per comment #3, the bisect information is as follows:

Bisect Information:
=====================
Bisect info: 507466 (good) - 507488 (bad)
Change Log:
-----------
https://chromium.googlesource.com/chromium/src/+log/8a6beb7a..0d40e427?pretty=fuller

Suspecting r507481 = f8f6ed59949be4451ee2f5443d8a313f102fde60 = https://crrev.com/c/668363 by mkwst@chromium.org
"Percent-encode UTF8 characters in URL fragment identifiers."
Landed in 63.0.3237.0

mkwst@ - Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.
Adding label RBS as it seems to be a recent regression. Please feel free to remove the same if not appropriate. 

Thanks...!!

Sorry I mixed up the expected and actual result.

It should be: 

Chrome Version       : 63.0.3239.84
URLs (if applicable) :
OS version           : 10.12.6 (16G29)

What steps will reproduce the problem?
type 'https://example.com?a=中文#b=中文' to url

What is the expected result?
it will be 'https://example.com?a=中文#b=中文'


What happens instead?
it will be 'http://example.com/?a=中文#b=%E4%B8%AD%E6%96%87'

After updating from 62 to 63, I found that value in hashtag will be decoded.
input: 'https://example.com?a=中文#b=中文'

in 62 still be: 'https://example.com?a=中文#b=中文'
but in 63 will be: 'http://example.com/?a=中文#b=%E4%B8%AD%E6%96%87'

I see nothing from change log.96%87'