The invention discloses an adjustable fixing frame for a solar panel. The adjustable fixing frame comprises a rotating rod, a bottom plate, a fixed rod, a first connecting column, a first fixed column, a second connecting column, a connecting plate, a first screw, a rotating block, a fixed seat, a second fixed column, a spring, a sliding block, a first moving rod, a limiting rod, a fixed block, amounting plate, a sliding seat, a second moving plate, a stop rod, a second screw, a rotating plate, a supporting rod, a supporting column and a moving block. Two ends of a center of another side of atop end of the bottom plate corresponding to the supporting column are welded to a bottom end of the fixed seat, and a top end of the fixed seat is attached to two ends of a center of another side ofa bottom end of the mounting plate corresponding to the supporting rod. The adjustable fixing frame has the advantages of simple structure and convenience in use, tedious steps of installing the solar panel are simplified, the installation efficiency is improved, at the same time, the disassembly and assembly of the solar panel are facilitated, the detection and maintenance of the solar panel arefacilitated, the adjustment of an angle between the mounting plate and the bottom plate is facilitated, and the power generation efficiency is improved.