A bottom nozzle filter device and a debris-resistant bottom nozzle that can be used in a fuel assembly of a light water reactor nuclear power plant. The bottom nozzle filter device (30) comprises a plurality of unit plates (31) spliced in sequence. A through fluid passageway is formed between adjacent spliced unit plates (31). The fluid passageway comprises a plurality of separately arranged straight fluid inlets (314), a plurality of separately arranged straight fluid outlets (315), and fluid branch passageways (316) in communication with the straight fluid inlets (314) and the straight fluid outlets (315). An outlet segment of each straight fluid inlet (314) in the middle position is in communication with two fluid branch passageways (316). An inlet segment of each straight fluid outlet (315) in the middle position is in communication with two fluid branch passageways (316). By means of the straight fluid inlets, the straight fluid outlets, and the fluid branch passageways, the coolant flow direction is controlled, thereby preventing unnecessary vortices, so that the pressure loss is effectively controlled. After large debris is filtered, the fluid enters the fluid branch passageway, and is filtered again through the fluid branch passageway, implementing segmented filtering, thereby improving the filtering effect.