A support having a transmission mechanism using a thin connecting piece includes a support base body, a transmission plate, a supporting plate and at least one thin connecting piece. The support base body has a base and brackets extending upwardly from the base. The distal end of the bracket is provided with a fixing sleeve. One end of the transmission plate is pivotally connected to the bracket. The supporting plate connected to the other end of the transmission plate. The supporting plate is provided with pivoting sleeves. The thin connecting piece is disposed on the transmission plate. Via this arrangement, the supporting plate can be kept vertical in synchronization with the swinging of the transmission plate. Thereby saving the space greatly and reducing the whole volume occupied by the support and peripheral elements. In this way, the assembling process is simplified, the productivity is increased, and the cost is reduced.