The invention relates to a communication machine widescreen displayer installation rack. According to the communication machine widescreen displayer installation rack, an existing sliding rail with the height of 39mm commonly used on an LCDKVM switcher is changed to a narrow sliding rail with the height of 19mm, and the bearing capacity is improved through thickening a horizontal plate of supporting strips of a bearing part. The 20mm space saved by the sliding rail is skillfully utilized and is used for containing a folded 16:9 LED (length, width and height sizes are 430.4mm, 254.6mm and 9.9mm), and an existing 4:3 LCD (length, width and height sizes are 396mm, 324mm and 18.5mm) is directly replaced on the premise that an existing cabinet facility is not changed. The installable height of the cabinet is 450mm. Therefore, on the condition that all functions are not changed, the space saved by the narrow sliding rail is used in design for compensating for the extra part of the 16:9 LCD. The communication machine widescreen displayer installation rack is simple in structure and convenient to use.