can we do good pixel art with mouse(no pixel by pixel) and how ?

To add to what was said, we do not know the specifications of a project (number and type of animations, is there equipment display or visual customisation, viewing angle, etc) OP is working on, so implying that the specific workflow (3d to sprites) is doomed to produce bad results is both myopic and factually wrong. There are thousands of examples of 2d games with "wooden" animation, as well as fluid 3d animation. Depending on the project's nature, one will work better than another

 

Should mention, if I understand the OP correctly.... He "Only" has a mouse.
I have no idea how he is coding a game without a keyboard. But regardless that pretty much wipes most 3d modelling software off the table. I don't think it can be done without hotkeys.

Absurdity of the original topic aside, it has spawned a wonderful discussion about various forms, strengths, and weaknesses of a great number of different animation types, digital and traditional. I hope the OP gets some inspiration from it and thanks guys!

 

I don't really recommend using 3d to attempt to get pixel art. It is much better suited for higher resolutions that would be too big for "traditional" pixel art, not impossible, but larger than the norm for the style.

I'm really thinking the OP has a keyboard. Its more likely they only have a mouse for drawing, not a tablet, etc... I technically could be wrong, but just typing forum posts on a PC would massively suck without a keyboard, just imagine actual code.