I have a Chinese font file, the size of the file is 7.693 MB. Due to the size of the ttf file, the site loads only slowly.
Is there any way to reduce the size of the .ttf font?
There are a few ways to reduce the size of a TTF file, but most of them require that you know the consequences, since they are lossy.
It's important that you understand that doing any of the above to the font (apart from the last one) has consequences in how well the font works or how many languages it supports properly, so you need to do a lot of testing.
One final important point is that by doing any of the above to the font (including, surprisingly, simply converting it to WOFF or EOT), you are legally creating a derivative work, for which you specifically need a license to do so from the font's author. Most commercial fonts probably won't let you create derivative works. A notable exception is an open license like the SIL OFL which specifically permits derivative works (if you change the name of the font).
I don't know if you speak Chinese or not, but in case you know what you are doing, you could subset the font and reduce it to the 3000-4000 most used glyphs. This should be enough to render most standard Chinese texts and could significantly reduce the file size (a Chinese font might come with over 20,000 glyphs). Do this only in case you master Chinese at least on an intermediate level or have someone who could help you identifying the subset of glyphs required for your purpose.
Here's a frequency list for the characters used in Mainland China. Unfortunately it is somewhat outdated (2004). It only contains 3500 characters, use it with caution. (the Xinhua Zidian lists approx. 10,000 characters and it is the most common character dictionary you will encounter in China). Given names might have any character, so a 3500 glyph subset will only cover the everyday language. Again, this is only for Mainland China. Taiwan and some overseas communities use other characters (the traditional ones). If you are not a Chinese speaker, you will need someone with expertise on this.