A low temperature grinding device for granular substance is disclosed. The device has a body, an injecting unit, a driving unit, a fixed grinding plate, a rotary grinding plate, and at least one cooling unit. The injecting unit connecting a hollow cavity of the body and having an opening. The driving unit has a driving axis protruding into the cavity. The fixed grinding plate is fixed inside the cavity and centrally aligned with the driving axis. The rotary grinding plate is disposed to be combined with the body and has a plate body, a plurality of grinding teeth and an extending portion. The cooling unit is adhered to a surface of the fixed grinding plate not facing the rotary grinding plate. When the rotary grinding plate is combined with the body, the center of the rotary grinding plate is aligned with the driving axis and receives the driving axis by the extending portion, and the grinding teeth face and distant from the fixed grinding plate with a predetermined interval, and the cooling unit produces a required low temperature within the interval.一種粒狀物低溫研磨裝置,具有一裝置本體、一注入單元、一驅動單元、一固定研磨盤、一轉動研磨盤及至少一冷卻單元。注入單元連接裝置本體的一中空腔室,並具一開口。驅動單元以一驅動軸凸出於中空腔室中。固定研磨盤的中心對準驅動軸而設置於中空腔室中。轉動研磨盤,可與裝置本體結合,具有一盤體、多個研磨齒及一延伸部。冷卻單元貼附於固定研磨盤之背對轉動研磨盤的一表面上。當轉動研磨盤與裝置本體結合時,轉動研磨盤的中心對準驅動軸且以延伸部承接驅動軸,研磨齒面對固定研磨盤且與固定研磨盤之間保持一預定距離,冷卻單元藉以於預定距離內產生所需低溫。1‧‧‧粒狀物低溫研磨裝置11‧‧‧裝置本體111‧‧‧中空腔室112a‧‧‧散熱導管112b‧‧‧散熱導管113‧‧‧散熱風扇12‧‧‧注入單元121‧‧‧第一開口122‧‧‧第二開口13‧‧‧驅動單元131‧‧‧驅動軸14‧‧‧研磨單元141‧‧‧固定研磨盤142‧‧‧轉動研磨盤143‧‧‧插銷件144‧‧‧壓縮彈簧145‧‧‧第一冷卻單元146‧‧‧可拆殼體149‧‧‧第二冷卻單元15‧‧‧顯示單元16‧‧‧控制單元17‧‧‧散熱單元18‧‧‧電源線d‧‧‧距離
