The invention provides a general fixing device for bicycle accessories. The device comprises an adjusting sleeve of which one end is provided with an opening, and an adjustable mounting seat which is mounted in the adjusting sleeve, wherein the adjustable mounting seat is movably connected with the adjusting sleeve and has a degree of freedom in the axis direction of the adjusting sleeve; a mounting base is arranged at one end without the opening of the adjusting sleeve and used for fixing the adjusting sleeve on a bicycle; the mounting base is arranged at the sidewall of the adjusting sleeve and used for fixing the adjusting sleeve on the bicycle. The device has the beneficial effects that the problem of mounting the accessories to different bicycles can be solved through the adjustable mounting seat; the problem of mounting of the accessories applied to the bicycles with similar models can be solved generally; the mounting base positioned at the sidewall of the adjusting sleeve enables a mounted sensor/ magnet or other accessories to be clung to a frame, so that the problem that the accessories are difficultly mounted due to small space between the frame and wheels can be solved; the device particularly has outstanding effects on solving the problems of mounting of the accessories onto the existing highway bicycle or fixed cog.