My husband is being charge with disorderly conduct. If he plead guilty can he still become US citizen?

As far as whether or not he should take the plea - your best bet is going to be to speak with your Criminal Defense attorney regarding that. You should also consult with an immigration attorney as well, so that they can assess the specifics of your husband's situation to determine how the disorderly conduct would impact his immigration status. There's a number of things that can factor into this, including a potential order of protection, whether he has criminal history, what his immigration status is (LPR or undocumented) etc.    With that being said, as far as some general information - misdemeanor assault (assault in the third degree) is a class "A" misdemeanor offense and can subject your husband to up to to a year in jail, as well as three years probation. Disorderly conduct on the other hand is a violation with a maximum penalty of 15 days in jail. Obviously the disorderly conduct is significantly less serious than the misdemeanor charge both from a Criminal and Immigration standpoint. With that being said, you can ask your defense attorney whether an adjournment in contemplation of dismissal is possible - if they're offering a disorderly conduct they may consider offering an ACD which essentially would adjourn his case for six months (on a non-family case) or a year (on a family case) and at the end it would be dismissed and sealed as if it never happened. With that being said, in certain circumstances, such as if he has an immigration hearing coming up during that ACD period, he may be better off with the disorderly conduct - again it all depends on his specific circumstances so your best bet is going to be to contact an Immigration lawyer and go over the specifics with them. I hope this information was helpful though.