The invention discloses a multifunctional curved-surface physical evidence image flattening instrument and belongs to the technical field of sampling. According to the multifunctional curved-surface physical evidence image flattening instrument, an object to be detected is automatically rotated and spread through a rotary objective table, an image control system sends a completion signal to a computer after the object to be detected is spread, then the computer controls starting and stopping of a CCD digital imaging system and an illuminating combined light source, a lifting control mechanism adjusts the height of the CCD digital imaging system and the height of the illuminating combined light source, a horizontal movement control mechanism adjusts the horizontal position of the rotary objective table, a control rotary motor adjusts the movement of an automatic adjustment arm so that the object can be fixed and regulates the rotating speed of the rotary objective table so that the object to be detected can rotate on the rotary objective table by a plurality of angles, the CCD digital imaging system is used for obtaining the image information, at any angles, of the surface of the object to be detected, the image information is transmitted to the image control system, and then image integration is achieved by conducting data processing. According to the multifunctional curved-surface physical evidence image flattening instrument, plane image information can be obtained from a curved surface through automatic rotation and scanning of the rotary objective table by means of corresponding image processing software.