In order to study the structure stability of prefabricated steel spring floating slab track and stress condition of shear dowel under side mounted shear dowels connection conditrons, based on the application example of a prefabricated steel spring floating slab track bed project on a domestic rail transit line, the stability of prefabricated steel spring floating slab track structure and the stress state of shear hinges under the condition of side mounted shear hinge connection are studied. A dynamic coupling analysis model of the train steel spring floating slab under four sets of side mounted shear dowels connection conditions is established using universal mechanism dynamic simulation software. The force of the shear dowel at each position and the stability of the track structure are analyzed under three working conditions of the train passing through a straight section, a curve radius R = 800 m, a cant 120 mm curve section, and a cant 105 mm curve section at a speed of $120$ km/h. Research has shown that when a train passes through a straight section, the force on the shear dowel in the slab is significantly greater than that on the edge of the slab. The force on the two sets of shear dowel in the slab is basically the same, and the force on the two sets of shear dowel on the edge of the slab is basically the same. The vertical displacement of the track bed under the left and right rails is basically the same and meets the limit requirements; When the train passes through the curved section, the force on the shear dowel in the middle of the slab is significantly greater than that on the edge of the slab, and the force on the shear dowel on the left rail (outer rail) side is significantly greater than that on the right rail (inner rail) side. The vertical displacement of the lower track bed of the left rail (outer rail) is greater than that of the lower track plate of the right rail (inner rail) and meets the limit requirements.