The invention belongs to the technical field of tool boxes, and relates to a tool box capable of being used as a desk. The tool box comprises a main box body, supporting legs, a handle, a buckle lock, a self-supporting hinge and an upper cover. Four supporting legs are self-locking joints with adjustable angles, each supporting leg is divided into two sections, each section can be independently adjusted, when a self-locking button stays at an un-pressed state, the supporting legs are at a locked state, the angle of the supporting legs can be adjusted by pressing the self-locking button, and the supporting legs can be locked again by releasing the self-locking button, so that the supporting legs are convenient to retract and stretch out. When the supporting legs are retracted, the tool box is the same with an ordinary tool box when viewed from the appearance, the overall structure is simple, and the tool box is convenient to carry; and when the supporting legs stretch out, the height of the desktop can be adjusted by adjusting the angle of the supporting legs, and the stability of the tool box can also be adjusted, so that the tool box can be applied to a complicated ground environment. By adopting the self-supporting hinge, the upper cover can be supported by the hinge when being opened, so that the side turning of the tool box is avoided.