The invention discloses a stuffing box for a piston rod of a crosshead two-stroke diesel engine. The stuffing box comprises a housing which is formed by two connected semicircular rings with flanges on lower end parts, wherein the flanges are fixed on an air cylinder transverse partition plate through bolts; four ring slots are formed in the inner surface of the housing from top to bottom in the axial direction; gas vent holes and oil return holes extending to the outside of the housing are formed in the ring slots; gas rings are mounted in the upper two ring slots; oil rings are mounted in the lower two ring slots; the gas rings and the oil rings comprise a plurality of sections of ring arcs which are of positive and negative step structures lapped up and down; at least one ring-shaped circular arc slot is formed in the peripheral surfaces of the gas rings and the oil rings; the circular arc slots are tied to the outer circles of the piston rod through springs in the circular arc slots, and are embedded into the ring slots; ring-shaped bumps are arranged on the peripheries of the ring arcs of the gas rings; sealing rings which are embedded into the sealing slots in the bottom of the ring slots are further arranged on the outer peripheral surfaces of the bosses. The stuffing box is simple in structure, and the gas rings and the oil rings are remarkably improved in sealing effect and oil scraping effect.