The invention belongs to the technical field of intelligent robots, and discloses a vision acquisition and calibration method based on a multi-degree-of-freedom mechanical arm. The method comprises the following steps that a designated point on the mechanical arm is kept fixed, and the mechanical arm is respectively rotated for one circle around at least two coordinate axes of a coordinate systemtaking the designated point as an original point; coordinates of each corner point on a calibration plate in the rotating process are obtained; a circle center coordinate of the motion track of the calibration plate and a space offset vector from each corner point to the designated point under a vision acquisition coordinate system on a designated frame are calculated; the posture of the mechanical arm is kept unchanged from the designated point to the tail end of the mechanical arm, and the mechanical arm is respectively translated towards different planes; a plurality of frames of images aresampled for the calibration plate in the translation process, and meanwhile the coordinates of the tail end of the mechanical arm are obtained through the mechanical arm system; and the transformation relation between the vision acquisition coordinate system and the mechanical arm coordinate system is calculated. By adopting the method, the coordinate system transformation relation between visionacquisition equipment and the mechanical arm system can be calculated without accurately fixing the calibration plate without measurement equipment.