H-4签过之后在国内等入境的时候,H1b的持有人在美国换了工作,这个一年有效的H-4签证还需要重新用新797签一遍吗? -Not need to get a new visa and the H4 visa is still valid, but you need to use your spouse's new H-1 (transfer) approval notice to enter US.