A system for realizing multi-user augmented reality, comprising: a primary computing device, and a secondary computing device comprising a secondary visual sensor, a processor and a storage device storing computer executable code, and the computer executable code, when executed at the processor, is configured to: receive information of a product from the primary computing device to obtain a three-dimensional, 3D, model of the product; receive a primary 3D map of an environment from the primary computing device; obtain secondary images captured by the secondary visual sensor; construct a secondary 3D map of the environment based on the obtained secondary images; align the secondary 3D map with the primary 3D map to form an aligned secondary 3D map; and upon receiving a position and orientation of the 3D model in the primary 3D map, place and render the 3D model of the product in a corresponding position and orientation in the updated secondary 3D map, characterised in that once the 3D model is moved or rotated on any one of the primary computing device and the secondary computing device, a transformation of the 3D model is transferred at real time from the one of the primary computing device and the secondary computing device to the other one of the primary computing device and the secondary computing device, such that the other one of the primary computing device and the secondary computing device synchronizes the moving or rotation of the 3D model in the 3D map. a primary computing device, and a secondary computing device comprising a secondary visual sensor, a processor and a storage device storing computer executable code, and the computer executable code, when executed at the processor, is configured to: receive information of a product from the primary computing device to obtain a three-dimensional, 3D, model of the product; receive a primary 3D map of an environment from the primary computing device; obtain secondary images captured by the secondary visual sensor; construct a secondary 3D map of the environment based on the obtained secondary images; align the secondary 3D map with the primary 3D map to form an aligned secondary 3D map; and upon receiving a position and orientation of the 3D model in the primary 3D map, place and render the 3D model of the product in a corresponding position and orientation in the updated secondary 3D map, characterised in that once the 3D model is moved or rotated on any one of the primary computing device and the secondary computing device, a transformation of the 3D model is transferred at real time from the one of the primary computing device and the secondary computing device to the other one of the primary computing device and the secondary computing device, such that the other one of the primary computing device and the secondary computing device synchronizes the moving or rotation of the 3D model in the 3D map. receive information of a product from the primary computing device to obtain a three-dimensional, 3D, model of the product; receive a primary 3D map of an environment from the primary computing device; obtain secondary images captured by the secondary visual sensor; construct a secondary 3D map of the environment based on the obtained secondary images; align the secondary 3D map with the primary 3D map to form an aligned secondary 3D map; and upon receiving a position and orientation of the 3D model in the primary 3D map, place and render the 3D model of the product in a corresponding position and orientation in the updated secondary 3D map, characterised in that once the 3D model is moved or rotated on any one of the primary computing device and the secondary computing device, a transformation of the 3D model is transferred at real time from the one of the primary computing device and the secondary computing device to the other one of the primary computing device and the secondary computing device, such that the other one of the primary computing device and the secondary computing device synchronizes the moving or rotation of the 3D model in the 3D map.