A cordless blind device that can be operated in various types such as manual, semiautomatic, and automatic types is proposed. The cordless blind device includes: a winding roll, a screen, a driving motor, a weight connected to a lower end of the screen; a torsion spring applying torque in a direction in which the screen is wound; and a rotation conversion module transmitting power in two directions between the driving motor and the winding roll, in which when the driving motor does not generate driving force, the torque applied by the torsion spring, the torque applied by the weight, and resistance by the rotation conversion module and the driving motor make equilibrium, so the screen remains stopped, and when an external force is applied upward or downward to the weight, the equilibrium of the forces breaks, so the screen is wound on or unwound from the winding roll.