The invention discloses longitudinally connected rail plates and a connecting method thereof and belongs to the technical field of longitudinally connected rail plates. The plates comprise a plurality of longitudinally connected rail plates, wherein the end of the rail plate is provided with a groove; a bearing platform of the rail plate is provided with a rail flange slope of 1:38 to 1:42; a shearing device is embedded on the groove; the shearing device comprises a connecting plate with an embedded reinforcing steel bar fixed on one side and a shearing plate fixed on the other side; the shearing plate is provided with teeth at least on one side; and the teeth socket direction of the teeth is vertical to the connecting plate. The connecting method comprises the step of engaging the shearing plates between two adjacent rail plates and then connecting by using bolts. The invention not only has simple structure, but also can efficiently transmit the shear stress on the longitudinally connected rail plates and spread to the adjacent rail plates, can efficiently decrease the function of a positive pressure on the rail plate end and can prevent the rail plates from being broken caused by subgrade settlement.