Disclosed is a learning method and device for alzheimer prediction model based on domain adaptation performed by at least one processor including extracting a point related to an object in a learning image from the learning image for a 3D reconstruction model, obtaining a gradient map including surrounding context information in three dimensions of the point from a 3D model of the object, determining a weight of the point based on the learning image and the gradient map, and learning the 3D reconstruction model by using the weight such that the 3D model of the object is output from the 3D reconstruction model into which the learning image is input.