The invention discloses a base regulating mechanism of a joint robot. The base regulating mechanism comprises a mounting plate, wherein the top of the left side of the mounting plate is fixedly connected with a supporting sleeve; a transmission base is connected inside the supporting base in a sliding mode; the top of the transmission base extends to the top of the supporting sleeve; a robot jointis arranged on the top of the transmission base; an opening is formed in each of the front end and the rear end of the right side of the supporting sleeve; and the right side of the supporting sleevecommunicates with a transmission box through openings. According to the base regulating mechanism disclosed by the invention, the transmission mechanism drives the screw to rotate, and the screw drives the transmission base to move upwards or downwards through a threaded sleeve and a connecting plate, so that the advantages of regulating height of the base and the horizontal joint robot are achieved, and therefore, the problem that a base plate with certain height needs to cushion for mounting the base as the base of the existing horizontal joint robot is not provided with certain height regulating mechanism is solved, practicability of the horizontal joint robot is improved, and use of people is convenient.