The invention discloses a system and method for recycling magnesium and magnesium alloy waste. The system comprises at least one melting furnace, wherein an air intake device is communicated to the bottom of a first crucible, inert gas is blown in from the bottom of a melt, and bubbles carry impurities in the melt to a liquid level; when a melting furnace inputs the melt into a thermal insulation casting furnace, and a first liquid outlet pipe is communicated to the part, close to the bottom, of the first crucible so as to ensure that the melt can not carry over the impurities; and a small amount of impurities are still contained in the melt after the impurities are removed, and the impurities are settled at a position, close to a feeding hole, inside the thermal insulation casting furnace, so as to ensure that the impurities settled at the bottom of a second crucible can not be carried over when the melt is transferred toward an ingot casting device, so that the impurity removing effect and efficiency are guaranteed. When the thermal insulation casting furnace transfers the melt toward the ingot casting device, at least one melting furnace completes impurity removing treatment, the melt is transferred toward the thermal insulation casting furnace, feeding to the ingot casting device is guaranteed, a continuous recycling process is realized, and the production efficiency is improved.