The invention discloses a calcium carbide preparation device and method. The calcium carbide preparation device comprises a pretreatment unit and a calcium carbide reaction unit, wherein in the vertical direction, the pretreatment unit is located above the calcium carbide reaction unit and comprises a pyrolytic reaction area, an oxygen thermal reaction area, a material inlet, an oxygen-containing gas inlet, a first exhaust outlet and a pretreated material outlet which are arranged from top to bottom; the calcium carbide reaction unit comprises a reaction space, an electrode, a pretreated material inlet, a second exhaust outlet and a calcium carbide outlet; the pretreated material inlet is connected with the pretreated material outlet. According to the calcium carbide preparation device, medium-and-low-order raw coal can serve as the raw material for calcium carbide preparation, heat generated in the preparation process can be fully utilized, and the heat utilization efficiency can be improved, so that the production cost can be remarkably lowered; furthermore, obtained calcium carbide is relatively high in quality.