A flexible-envelope type battery and an electrically conductible sealing structure thereof and an assembling method thereof are provided. The battery includes an electrode pair, a flexible envelope and a pair of electrically conductible sealing structures. Each sealing structure includes a conductive terminal and a fixed member. The conductive terminal includes a bottom board and a protruding block, for conducting an electric current from the electrode pair to the outside. The bottom board is disposed within the flexible envelope and combined with the electrode pair. The protruding block is disposed on the bottom board for passing through and protruding from an upper surface of the flexible envelope. The fixed member is for tightly fixing the flexible envelope and the conductive terminal.