Can a lawyer bring a phone when meeting his client?

No problem, but lawyers can't give mobile phones to defendants or criminal suspects. Otherwise, it will be sanctioned by law.

Paragraph 1 of Article 37 of the Criminal Procedure Law: A defense lawyer may meet and correspond with a criminal suspect or defendant in custody. Other defenders, with the permission of the people's courts and people's procuratorates, may also meet and correspond with criminal suspects and defendants in custody.