The invention relates to an end sealing structure of a through-wall casing pipe so as to solve the problem that in the prior art, only one-time sliding sealing is adopted between a conducting rod of athrough-wall casing pipe and a connecting flange of the end of the casting pipe and thus the sealing effect is poor. The connecting flange is covered with a sealing cover matched with the connectingflange in a sealed mode, the sealing cover is provided with a sealing cover penetrating hole for allowing a conducting rod or a conducting lead-out rod connected with the end of the conducting rod topenetrate out, and the conducting rod or the conducting lead-out rod is matched with the sealing cover penetrating hole in a slidably sealed mode. The conducting rod moves in the axial direction of the conducting rod. The conducting rod and the connecting flange are matched in a slidably sealed mode to achieve primary sealing, the sealing cover is arranged on the connecting flange in sealed and matched modes, and the conducting rod or the conducting lead-out rod and the sealing cover are subjected to secondary sliding sealing, so that the sealing effect is reinforced. If an insulation medium in a containing cavity is in a high-pressure state, the primary sliding sealing effect is poor, the insulation medium leaks into the sealing cover to reduce the pressure, and the secondary sliding sealing effect can achieve the good sealing effect accordingly.