Insulation board assembly structure for building external wall insulation

The utility model discloses an insulation board assembly structure for building external wall insulation, which comprises a main wall body and a rotating nut, a twisted steel column is welded inside the main wall body, connecting mortar is arranged on the left side of the main wall body, a fixed expansion head is arranged on the left side of the connecting mortar, and the fixed expansion head is connected with the rotating nut. Clamping and fixing devices are arranged on the left sides of the fixed expansion heads, connecting stripe plates are arranged on the left sides of the clamping and fixing devices, assembling heat preservation plates are arranged on the left sides of the connecting stripe plates, groove plates are arranged on the left sides of the assembling heat preservation plates, and rubber gaskets are arranged on the left sides of the groove plates; mounting nail caps are arranged on the left sides of the rubber gaskets correspondingly, and the rotating nuts are arranged on the outer sides of the