The invention relates to a movement-adjustable installation platform for a circular shaft clamping mechanism, which is characterized by comprising a middle sliding platform and a driving mechanism, wherein the middle sliding platform is used for installing a clamping mechanism; the driving mechanism is used for driving the middle sliding platform to move; the middle sliding platform is arranged on a bed body through linear sliding rails; the middle sliding platform comprises a middle sliding platform flat plate, small guiding rails and small adjusting plates; each of the left end and the right end of the middle sliding platform flat plate is provided with two small guiding rails which are arranged horizontally and transversely; one small adjusting plate is arranged above each of the left end and the right end of the middle sliding platform flat plate; a sliding guiding fit is formed by each small adjusting plate and the corresponding small guiding rails; each small adjusting plate is provided with one set of clamping components; each small adjusting plate is connected fixedly with the middle sliding platform flat plate through bolts. According to the movement-adjustable installation platform for the circular shaft clamping mechanism, the structure is simple, the design is reasonable, the operation is convenient, the adjustable degree is wide, the movement is precise, the boring-milling machining efficiency and machining precision of a circular shaft are beneficially improved, and the labor intensity is lowered.