The disclosure relates to techniques for scan preparation in a medical imaging system. The technique includes triggering a 3D camera acquiring a 2D color and depth image of a patient when a patient bed is at an origin position, inputting the image into a pre-trained first body information model to obtain position information of multiple body feature site points, and calculating position information of multiple candidate scanning regions in the patient bed coordinate system. The technique further includes providing the position information of the multiple candidate scanning regions to a medical imaging application apparatus, so that the medical imaging application apparatus determines position information of a current scanning region in the patient bed coordinate system and controls the patient bed to move the current scanning region to a scanning center of a medical imaging device according to the position of the patient bed relative to the scanning center.