你可以在combobox1的OnChange事件里写代码
adoquery1.Close;
adoquery1.SQL.Clear;
adoquery1.SQL.Add('SELECT distinct XXX from CPU where brand='''+combobox1.text+'''');
adoquery1.Open;
combobox2.Items.Clear;
while not adoquery1.Eof do
begin
combobox2.Items.Add(adoquery1.fieldbyname('XXX').AsString);
adoquery1.Next;
end;
依次类推,在combobox2的OnChange事件再写事件啊!