A power connector for building blocks has a loading sheet adapted to be mounted between two assembled building blocks and a socket mounted on the loading sheet. The loading sheet has a locating segment and a conducting unit. The locating segment forms a through hole. The conducting unit is mounted on a surface of the locating segment. The socket is electrically connected to the conducting unit and is used to connect to a wire. The power connector is mounted between the two assembled building blocks by the loading sheet and is mounted around any column of another building block via the through hole. Thus, the power connector is mounted on the building blocks without pasting and drilling and therefore without breaking the building blocks. Besides, the power connector is manufactured by automation so that cost is reduced and the quality is stable.