i have a suzuki 2007 xl7 it hase a over heating problem had it flush but it still over heating what can it be

Did you check fan works properly? worst case try bypass on thermostat. So you can see if it was thermostat problem.

Should have had that thermostat replaced when they did the coolant flush, so that and possible bad water pump, the impeller gets eroded away, or a bad head gasket, which a test can be done to determine if there are exhaust gasses in the cooling system. And I assume the cooling system had be purged from the air pockets.