The invention relates to the technical field of a high-voltage switchgear, and in particular to an electrical connection structure in a switchgear, a closed main bus and a gas-insulated metal-enclosed switchgear. The gas-insulated metal-enclosed switchgear comprises the closed main bus, wherein the closed main bus comprises the electrical connection structure, the electrical connection structure comprises an electrical connection seat and a conductive rod, one of the electrical connection seat and the conductive rod is provided with a male connector, the other one of the electrical connection seat and the conductive rod is provided with a female connector, touch fingers are arranged on a contact surface of the electrical connection seat and the conductive rod, and first heat dissipation holes are formed in the female connector and are corresponding to the touch fingers. The heat dissipation holes are formed in the conductive rod or the electrical connection seat and are corresponding to the positions of the touch fingers, so that heat generated at the touch fingers can be dissipated to a part outside the electrical connection structure through the shortest path and with the fastest speed, the temperature rise of the electrical connection structure is effectively reduced, the electrical connection structure can bear larger current flowing quantity, and the current-through capability of the closed main bus is improved.