The invention provides a nozzle for polycrystalline silicon reduction furnaces with 48 pairs of sticks. The nozzle belongs to the production field of polycrystalline silicon. The nozzle mainly comprises a cylinder core. The core consists of a first inner tube and a first outer tube. The first outer tube is set and covered on the first inner tube. The first inner tube comprises a main channel. The flow area of the air outlet of the main channel is smaller than the air inlet. The gap between the first outer tube and the first inner tube forms an auxiliary channel. The core is installed on a chassis through an interconnecting piece. Due to the flow area of the air inlet is larger than the flow area of the air outlet, air is passing through the main channel with an increasingly faster speed and eventually reaches the top of the reduction furnace. After passing through the auxiliary channel, a part of the air in the auxiliary channel gets to the middle of the reduction furnace, and the other part of the air gets to the bottom of the reduction furnace through a plurality of side vent holes on the first outer tube. The material gas can be evenly distributed in the entire reduction furnace, which leads to the fully performing of the reduction reaction.