A device and method for controlling the speed of a rolling door is disclosed. The door panel is controlled to accelerate or decelerate by means of the real-time rolling speed of the door panel, such that speed control is applicable to door panels of different specifications. When the real-time rolling speed of a door panel reaches a predetermined acceleration value, a control module actuates the driving module to speed up opening or closing of the door panel. When the real-time rolling speed of the door panel reaches a predetermined deceleration value, the control module controls the driving module to speed down opening or closing of the door panel; when the real-time rolling speed of the door panel is in between the acceleration value and the deceleration value, the control module actuates the driving module to maintain the opening or closing speed of the rolling door at current value.