Adjustable fixing device

The invention provides an adjustable fixing device which comprises a fixing bottom plate, wherein three support threaded rods extending vertically are mounted on the fixing bottom plate in a screwing manner; a mounting plate for fixing a supported piece is supported by and matched with the upper ends of the support threaded rods; at least one of the three support threaded rods can move vertically relative to the fixing bottom plate to allow the mounting plate to incline; the fixing bottom plate is provided with screw penetrable holes in the interior of the triangle taking the three support threaded rods as vertexes; set screws are arranged in the screw penetrable holes in a vertically penetrating manner; the upper ends of the set screws are connected with the mounting plate; the set screws are assembled with locking nuts on the lower side of the fixing bottom plate; and the locking nuts compress the fixing bottom plate upwards to lock and fix the fixing bottom plate and the mounting plate. The adjustable fixing device can realize the effect of adjusting an angle and a position of the supported piece; the mounting plate can be locked or loosened simply by screwing or loosening the locking nuts on the set screws; the adjustable fixing device can be dismounted simply by screwing the set screws; and the adjustable fixing device is simple in structure and convenient to operate.