I had surgery on my foot 3 weeks ago stitches are off and the skin around the cut is peeling off, I could see the second layer skin is it normal?

Yes . Yes it is totally normal. Don't pick or peel it though, it will peel off when it is ready.
Normal Healing. Peeling is healing ! signs of infection: redness streaking swelling warmth pain loss of funtion drainage symptoms of infection: fever chils nausea vomiting.
Talk to your surgeon. It is probably important to know what surgery you had and whether you have followed up per your schedule. Regardless, it warrants a call to your surgeon's office to discuss this matter/concern.
Surgery . It usually is normal and the skin you see is the skin replacing the layer peeling away. If you are concerned , see your surgeon.