How to maintain the original settings, such as fonts after theme changing?

[Grant-S-Z]

With the theme changing, the fonts change too. Any way to avoid that?

[swflint]

What themes are you using? I suspect that one or both of the themes sets some font settings.

Note, you could add a function to theme-changer-post-change-hook (which, see) which unconditionally sets the font to your preference.

[Grant-S-Z]

I use the two themes: doom-one-light and doom-one.
My related settings:

(add-to-list 'load-path "~/.emacs.d/repos/theme-changer")
(require 'theme-changer)
(change-theme 'doom-one-light 'doom-one)

(use-package emacs
  :init
  (progn
    (set-face-attribute 'default nil    ;:font "Fantasque Sans Mono"
					:font "Inconsolata"
					:height 130)
    (dolist (charset '(kana han symbol cjk-misc bopomofo))
      (set-fontset-font (frame-parameter nil 'font)
			charset (font-spec :family "LXGW WenKai")))))

I think fonts settings will not be loaded when the themes transfer.
As for adding to theme-changer-post-change-hook, it seems like a good idea. I'll try it later.