I want to make it more beautiful  

RE: I want to make it more beautiful

That's the problem with FDM technology--you need supports for overhangs, and there will always be remnants of it unless you can use soluble supports. You can try and play with support settings but more likely or not the only way to get a nice look is post-processing aka sanding and polishing. 

For a smoother under surface you need soluble supports.

Cheerio,

RE: I want to make it more beautiful

That looks like a fairly small piece, and the smaller the pieces, the more things like support interfaces will show.

If this were my project, I would think critically about it and consider such things as re-designing for minimizing supports, perhaps breaking up the project into pieces that could be printed either with no support or with 'greasy side down' supports, and also thinking about how the piece or pieces could be positioned on the build plate to minimize break-away support scars.

RE: I want to make it more beautiful

That looks like a fairly small piece, and the smaller the pieces, the more things like support interfaces will show.

If this were my project, I would think critically about it and consider such things as re-designing for minimizing supports, perhaps breaking up the project into pieces that could be printed either with no support or with 'greasy side down' supports, and also thinking about how the piece or pieces could be positioned on the build plate to minimize break-away support scars.

good idea

RE: I want to make it more beautiful

i think this is already looks so good

RE: I want to make it more beautiful

@ykk2022

Can you tell me if there is a way to improve it?

Yes, but you will have to educate yourself first, you are very far from a reasonable understanding of how to tune your models in PrusaSlicer. I would have to spend months with you to explain what you don't know. If you have it in you to stick with this you will get better, however you will have to put in the time and start with more simple situations, before you are there.

Good Luck

Swiss_Cheese

RE: I want to make it more beautiful

Posted by: @jsw

That looks like a fairly small piece, and the smaller the pieces, the more things like support interfaces will show.

If this were my project, I would think critically about it and consider such things as re-designing for minimizing supports, perhaps breaking up the project into pieces that could be printed either with no support or with 'greasy side down' supports, and also thinking about how the piece or pieces could be positioned on the build plate to minimize break-away support scars.

+1 agree

you will be surprised how well two pieces can fit together