Hi,
If your husband has residential ties to Canada, he will be considered to be a Canadian resident for tax purposes and hence, he will be taxed in Canada on all income earned (worldwide) . For more information on residency in Canada, please visit http://www.cra-arc.gc.ca/tx/nnrsdnts/cmmn/rsdncy-eng.html . The CRA website has very helpful information regarding this matter
Sincerely,
Madan CA