A computer implemented method for automatically annotating a target object in a plurality of images, wherein the method comprises: obtaining, for a target object, an image training sample comprising the plurality of images, each image of the plurality of images obtained by photographing the target object, wherein the position of the target object remains unchanged during the image acquisition, wherein the obtaining the image training sample comprises obtaining a target video file and using a plurality of images in the video file as the plurality of images of the image training sample, the target video file being obtained by photographing the target object in a target environment, wherein adjacent images of the plurality of images share a plurality of environmental feature points, and wherein the target video file is captured by: placing the target object and a marker having a planar structure in the target environment, the plane of the marker being placed in parallel to a horizon; aiming a lens of an imaging device at the marker for photographing; and moving the lens of the imaging device to a position of the target object for photographing; determining a three-dimensional reference coordinate system, the determining the three-dimensional reference coordinate system comprising establishing the three-dimensional reference coordinate system based on a plane at which the marker is located in first several frames of the video file; generating a three-dimensional model based on the three-dimensional reference coordinate system, wherein the three-dimensional model is a regular object or composite object formed by regular objects; determining position information of the target object in the three-dimensional reference coordinate system, said determining position information being performed when the three-dimensional model has been moved by a user to a position enclosing the target object in a reference image, wherein the reference image is one of the plurality of images; and mapping the three-dimensional model to image planes of each image in the plurality of images, other than the reference image, based on the position information of the target object in the three-dimensional reference coordinate system and respective camera pose information corresponding to each image in the plurality of images, the respective camera pose determined based on environmental feature points in each image. obtaining, for a target object, an image training sample comprising the plurality of images, each image of the plurality of images obtained by photographing the target object, wherein the position of the target object remains unchanged during the image acquisition, wherein the obtaining the image training sample comprises obtaining a target video file and using a plurality of images in the video file as the plurality of images of the image training sample, the target video file being obtained by photographing the target object in a target environment, wherein adjacent images of the plurality of images share a plurality of environmental feature points, and wherein the target video file is captured by: placing the target object and a marker having a planar structure in the target environment, the plane of the marker being placed in parallel to a horizon; aiming a lens of an imaging device at the marker for photographing; and moving the lens of the imaging device to a position of the target object for photographing; placing the target object and a marker having a planar structure in the target environment, the plane of the marker being placed in parallel to a horizon; aiming a lens of an imaging device at the marker for photographing; and moving the lens of the imaging device to a position of the target object for photographing; determining a three-dimensional reference coordinate system, the determining the three-dimensional reference coordinate system comprising establishing the three-dimensional reference coordinate system based on a plane at which the marker is located in first several frames of the video file; generating a three-dimensional model based on the three-dimensional reference coordinate system, wherein the three-dimensional model is a regular object or composite object formed by regular objects; determining position information of the target object in the three-dimensional reference coordinate system, said determining position information being performed when the three-dimensional model has been moved by a user to a position enclosing the target object in a reference image, wherein the reference image is one of the plurality of images; and mapping the three-dimensional model to image planes of each image in the plurality of images, other than the reference image, based on the position information of the target object in the three-dimensional reference coordinate system and respective camera pose information corresponding to each image in the plurality of images, the respective camera pose determined based on environmental feature points in each image.