The 4U server chassis is also called a 2u rack server chassis. The rack is called a 19-inch rack, U is a unit that represents the height of the server outside, and the height of 4u server chassis is 44.445mmX4 times. 2u server chassis is an important part of the server accessories. Its main function is to place and fix each server accessory, which plays a supporting and protecting role. In addition, the computer chassis has an important role of electromagnetic radiation shielding. It is sconstituted a chassis shell, a bracket, a cooling fan, a hard disk connection board, a hard disk box, a panel, a switch, and an indicator light.