Provided are a method for cutting silicon rod and an apparatus for diamond multi-wire cutting, the method for cutting silicon rod includes: using a cooling pipe to supply cutting fluid to the diamond wire, and using the diamond wire to cut the silicon rod, wherein the distance between the supply position of the cutting fluid and the periphery of the silicon rod is 10-20 mm; or adjusting the new wire running amount and/or feed speed at different positions of the crystal cross section during the cutting process.