Disclosed is a lifting structure for a computer desk on a bed. The problem that a user has sore waist and back when sitting long when the laptop desk on the bed is used but a keyboard cannot be seen if a user sits down resulting in inconvenient using is solved. The desk is characterized in that a baffle plate is arranged on the long side edge of the desktop of the laptop desk, and the baffle plateis connected with fixed pulleys, so that the baffle plate can be tightly adhered to the desktop or separated from the desktop, supporting legs are arranged on four corners below the desktop, a plurality of circular holes with the same and appropriate size are equidistantly formed in appropriate positions on the upper portions of the supporting legs, each lower portion of the supporting leg is arranged in one of the circular holes with the same size of the upper portion, the upper portions and the lower portions of the supporting legs are connected by screws, and the supporting legs are fixedthrough screw caps. The structure has the advantages of being simple in structure and operation, low in cost and worthy of popularization and application.