Hi @奔跑吧蜗牛c
Looks like you are using the Office365Users connector to display person.
Set the Items property of the Person Combo box to
Office365Users.SearchUser({searchTerm: ""})
Set the DefaultSelectedItems property to
Office365Users.MyProfile()
Set the Update property of Card to
{
Claims: "i:0#.f|membership|" & AssignedToCombo.Selected.Mail,
Department: "",
DisplayName: AssignedToCombo.Selected.DisplayName,
Email: AssignedToCombo.Selected.Mail,
JobTitle: "",
Picture: ""
}
Reference

Thanks,
Stalin - Learn To Illuminate