Hello, I have some questions on this object.
1. How can I draw this object? Should I use the loft feature to create the main body? Then how can I cut the holes on the curve surface?
2. If I have received this parts and I want to fill the holes, how should I do?
Big thanks.
1. It is difficult to give very detailed suggestions without seeing the model itself. But you may be able to use a loft with guide curves for the main body. It is hard to tell from the picture what the exact hole geometry is, but it's possible that they could be created by drawing a 2D sketch of the circles on a plane that is up off of the part, then cut extrude with the end condition set to offset from surface, choosing the part surface as the selection.
2. One thing you could try to remove the holes is to use Delete Face with the 'Delete and patch' or 'Delete and fill' option, and delete the hole bottoms and walls. Or if that doesn't work you could try to delete the walls and bottoms and then Untrim.