The invention provides an adjustable computer support. The adjustable computer support is used for placing a display and a keyboard of a desktop computer. The adjustable computer support comprises a base, stand columns, a movable rod, a pair of two-section sliding rails and a limiting rod, wherein the base is installed on the table top, the stand columns are installed on the base, the stand columns are in a U shape, and the stand columns are provided with U-shaped grooves; the movable rod is provided with a U-shaped plate part; one two-section sliding rail is connected between the left side ofthe U-shaped plate part and the left inner walls of the U-shaped grooves, and the other two-section sliding rail is connected between the right side of the U-shaped plate part and the right inner walls of the U-shaped grooves; the limiting rod is pivoted on the vertical columns, the front end of the limiting rod is provided with a limiting column, and the limiting column can penetrate into through holes of the U-shaped plate part, so that the relative position of the movable rod and the stand columns is determined; and the rear end of the limiting rod is provided with a pressing plate part, so that the limiting column can penetrate into the through holes or be separated from the through holes. According to the adjustable computer support, the height of the computer support can be conveniently and quickly adjusted, a user has good comfort during operation, and fatigue is relieved.