The utility model relates to a composite tower with an inside vertical ground down lead. A ground wire cross arm in the tower is made of metal materials, an ground down lead upper metal cross arm in certain length is led from the center of the ground cross arm along a lead direction, the ground down lead is led from the tail end of the upper metal cross arm vertically, is connected to the tower through a ground down lead lower metal cross arm at a position distant from the lower side of bottom-phase leads by certain distance and then is grounded downwards along the tower body, and if the lower portion of the tower adopts steel pipes, the ground down lead can be connected to the steel pipes so as to be grounded. By the aid of the additional ground down lead upper metal cross arm and the additional ground down lead lower metal cross arm, the ground down lead at the head of the tower is spaced from the body of the composite tower by a certain distance. By the aid of the composite tower with an inside vertical ground down lead, the power frequency pollution flashover resistance capacity of lines is enhanced, lightning surge insulating strength of the lines is strengthened, and composite insulators can not be burnt by flow current after lightning flashover. In addition, the composite tower with an inside vertical ground down lead is simple in structure and easy to be carried out.