A collapsible computer desk includes a desktop, a left frame, a right frame, two inner side-plates, a lower frame, plural middle support plates, a back plate and a drawer. The inner side-plates are secured to the desktop and also secured to the both ends of the lower frame. The back plate is connected to the back portion of the lower frame and the bottom surface of the desktop. Further comprised is a plurality of assembled closures. Each assembled closure is constructed of a male closure and a female closure. The male closures of the plurality of the closures are fixedly secured onto vertical plates of the left and right frames respectively, while the female closures are fixedly secured onto the both ends of the lower frame respectively. Each male closure detachably engages the corresponding female closure.