回複：863211/皮匠：H1B轉B簽證，+ 加拿大PR在美找工作？

1. file I-539 to change to B2 status. (not B visa)
2. no advantage. You need to have Canada passport to enjoy more non-immigrant benefits based on US-Canada treaty.
3. I-539 COS first. Canadian PR without strong ties with Canada is not necessarily easier to get US B visa. Not much different from other PRC passport holders (with or without Canadian PR).