是要先去美國的加拿大使館簽證，
-Yes.
到加拿大後去美國使館簽證。對嗎？
-No if you will return to US within 30 days. You just bring your passport, H1 approval notice with the I-94 and your recdent 3 month paycheck stub to return to US. Don't submit the I-94 to the airlines or the CBP officer when you leave US.
If you will stay in Canada for > 30 days, you need to 去美國使館簽證 to get the H1 visa to come back.
