A couple wanna file divorce. But her husband is in Canada and wife is here in SL. So my question is. Should husband come to SL to file divorce?

I am not sure what SL refers to. I presume you are talking about filing divorce in NJ. Husband or wife can only file for divorce if the party has resided here for at least a year before filing a complaint. If wife has lived her for more than a year, she could file, but the husband would not be able to file if he is residing in Canada.