Subdivision surface with sharp edges

I tried to make a smooth surface by subdivision function, however it modified the object like this… How can I use it to generate a object without any sharp edges?

your topology must be bad, please show the wireframe

maybe you have overlapping vertices? try an Alt M > Merge By Distance
if it doesn’t work please share your file:


you need to share the link :wink:

head1.blend (786.5 KB)

you have flipped normals (as seen below), so go in Edit mode, select all, press Alt N (or Mesh > Normals) > Recalculate

that’s work! Thank you very much!