A volume measuring apparatus for measuring a volume related data of a target box, comprising: a shell; a processing unit, arranged in the shell; a structure light emitting unit, arranged on a first surface of the shell, electrically connected with the processing unit, and emitting invisible structure light for forming a reference pattern when being triggered; a first camera, arranged on the first surface of the shell, electrically connected with the processing unit, and controlled by the processing unit to capture a left image, wherein the left image comprises an image of the target box and an image of the reference pattern; and a second camera, arranged on the first surface of the shell, electrically connected with the processing unit, and controlled by the processing unit to capture a right image, wherein the right image comprises the image of the target box and the image of the reference pattern; wherein, the processing unit is configured to perform a computation based on the image of the target box and the image of the reference pattern in the left image and the right image for generating a depth graph, and the processing unit is configured to scan the depth graph through multiple scanning lines (61,62) for determining a middle line, a bottom line, a left-side line, and a right-side line of the target box in the depth graph; characterised in that the processing unit is configured to scan the target box in the depth graph within a range of the middle line, the bottom line, the left-side line, and the right-side line via the multiple scanning lines (61,62) for obtaining multiple width information, multiple height information, and multiple length information, and the processing unit is configured to compute the volume related data of the target box according to the multiple width information, the multiple height information, and the multiple length information. a shell; a processing unit, arranged in the shell; a structure light emitting unit, arranged on a first surface of the shell, electrically connected with the processing unit, and emitting invisible structure light for forming a reference pattern when being triggered; a first camera, arranged on the first surface of the shell, electrically connected with the processing unit, and controlled by the processing unit to capture a left image, wherein the left image comprises an image of the target box and an image of the reference pattern; and a second camera, arranged on the first surface of the shell, electrically connected with the processing unit, and controlled by the processing unit to capture a right image, wherein the right image comprises the image of the target box and the image of the reference pattern; wherein, the processing unit is configured to perform a computation based on the image of the target box and the image of the reference pattern in the left image and the right image for generating a depth graph, and the processing unit is configured to scan the depth graph through multiple scanning lines (61,62) for determining a middle line, a bottom line, a left-side line, and a right-side line of the target box in the depth graph; characterised in that the processing unit is configured to scan the target box in the depth graph within a range of the middle line, the bottom line, the left-side line, and the right-side line via the multiple scanning lines (61,62) for obtaining multiple width information, multiple height information, and multiple length information, and the processing unit is configured to compute the volume related data of the target box according to the multiple width information, the multiple height information, and the multiple length information.