The invention provides a preparation method for a high fine rubber powder and a production line thereof. The preparation method for the high fine rubber powder prepared by using waste rubber comprises of smashing and resolving the waste rubber; and rolling the waste rubber after being smashed and resolved so as to obtain coarse rubber powder; milling and then accurate grinding the coarse rubber powder, so as to obtain fine rubber powder; refrigeration rubbing the fine rubber powder, so as to obtain high fine rubber powder. Wherein, milling and accurate grinding are conducted at room temperature and refrigeration rubbing is conducted at the brittle temperature of rubber. The preparation method for high fine rubber powder and production line thereof provides a production line for preparing high fine rubber powder by using waste rubber. The production line comprises smashing system, granulation system, milling and accurate grinding system and refrigeration rubbing system. Wherein, the milling and accurate grinding are conducted at room temperature and the refrigeration rubbing is conducted at the brittle temperature of rubber.