Cooling device for crystal casting furnace and method for casting crystals

The present invention provides a cooling device for a crystal casting furnace and a method for casting crystals. The crystal casting furnace comprises a crucible allowing seed crystals and solid-state silicon raw material to be arranged, the cooling device is arranged below the crucible and comprises a pedestal, at least one cooling groove and at least one channel for allowing fluid to pass through are disposed on the pedestal, the cooling grooves are corresponding to corner areas at the bottom of the crucible, and the channels communicate the cooling grooves with the outside of the pedestal. The method for casting the crystals comprises the step of injecting the fluid into the channels on the pedestal in a stage of melting the silicon raw material so as to enable the fluid to cool the corner cares at the bottom of the crucible to take away too much heat energy, so that the seed crystals positioned at the corner areas of the crucible are prevented from being completely melted.