The invention discloses a nonlinear vibration isolator for a floating slab rail system in rail traffic. The nonlinear vibration isolator for the floating slab rail system in rail traffic comprises vibration isolator cellulars, conical rubber, rigid springs, metal inner rings, protruding blocks and grooves. The conical rubber is arranged inside one vibration isolator cellular, wherein the rigid springs are arranged inside the conical rubber. The metal inner rings are fixed to the positions, on the upper ends of the rigid springs, of the tops of the vibration isolator cellulars. The protruding blocks are arranged on the upper surfaces of two sides of the vibration isolator cellulars. The grooves are formed in positions, corresponding to positions of the protruding blocks, in the lower surfaces of the vibration isolator cellulars. According to the nonlinear vibration isolator for the floating slab rail system in rail traffic, the vibration isolator cellulars are stacked by three layers inthe vertical direction so that the vibration isolator is formed; besides, the rigid springs are connected in parallel in the vibration isolator; and due to the arrangement, the vibration isolator ischaracterized in that the bearing capacity is high, the deformation space is little, and the intrinsic frequency can be low any.