You can select the font you like and install in your system in the corresponding drop-down list box, so that it can be displayed correctly after setting and entering the formula. It is suggested to use "Times New Roman" font for variables and "Symbol" font for lowercase Greek letters and symbols. General windows systems install these two fonts by default.
If what you see in Word is garbled, but what you see after entering the formula editor is the correctly displayed formula, then it will become garbled after exiting the formula editor. In fact, this is because the formula is automatically displayed in the formula editor in the font supported by your system, but it is not updated in the word document. At this time, you only need to click "File-Update Document …" in the formula editor or press the shortcut key "Ctrl+S" to update the formula font into the document, and then you can see that the formula has been displayed normally after exiting.
If you can't find the download of symbol.ttf from the Internet, you can try this method, that is, directly modify the existing font of this machine. The method is to open the formula editor in the Word document, then find the style in the menu bar in the upper left corner, and then select the definition. Then the Chinese font is Song Ti, and others, including Greek letters, choose "Times New Roman", which is our most commonly used font. The problem is solved!