Disclosed are a vehicle suspension spring device and a vehicle suspension system having the same. The vehicle suspension spring device includes a leaf spring unit comprising at least one leaf spring disposed in a lateral direction of a vehicle, a pair of first coupling parts provided at opposite ends of the leaf spring unit in a longitudinal direction and rotatably coupled to a pair of axles on which opposite wheels of the vehicle are mounted, and a pair of second coupling parts provided at two points between the opposite ends of the leaf spring unit in the longitudinal direction to be rotatably coupled to a subframe of the vehicle.