The utility model relates to an urea aqueous solution filter equipment with freeze proof protect function. Including the casing and with the outer end cover of casing matched with, be equipped with bythe upper end cover in the casing, the filter core that bottom end cover and filter media welding formed, be equipped with elastic rubber sleeve in the filter core, elastic rubber sleeve is sealed for one end, casement gum cover during one end is open, just this opening end is airtight continuous with outer end cover outside the upper end cover for this elastic rubber sleeve's opening end overhang, leave the clearance between elastic rubber sleeve's outer wall and the upper end cover, the ventilation valve who is equipped with with the inside intercommunication of elastic rubber sleeve is covered to the outer end, elastic rubber sleeve communicates with each other through the ventilation valve and the external world, be equipped with entry and export on the casing. According to the abovetechnical scheme, the utility model discloses an at inside freeze proof component - - - the elastic rubber sleeve who sets up a hollow structure of filter core, when urea solution when the filter chamber in was frozen, usable elastic rubber sleeve's deformation provided the compensation to filtering medium volume expansion, simultaneously, the convenience is installed and removed to this filter equipment's filter core.