A method for acquiring a depth image, comprising: emitting light to a target object; receiving light reflected by the target object and performing sampling a number of times, to obtain a plurality of phase maps; filtering the plurality of phase maps to obtain a plurality of filtered phase maps; and forming the depth image according to the plurality of filtered phase maps; whereby filtering the plurality of phase maps comprises: obtaining an amplitude map according to the plurality of phase maps; characterised in that filtering the plurality of phase maps further comprises: obtaining a confidence map by filtering the amplitude map; and filtering the plurality of phase maps by employing a joint bilateral filtering scheme and using the confidence map as a guiding map; wherein filtering the plurality of phase maps by employing the joint bilateral filtering scheme and using the confidence map as the guiding map comprises: segmenting each of the plurality of phase maps into a low confidence map and a high confidence map according to the confidence map; and filtering the high confidence map obtained from each of the plurality of phase maps with the joint bilateral filtering scheme to obtain a filtered high confidence map, wherein each of the plurality of filtered phase maps is obtained by processing the low confidence map obtained from each of the plurality of phase maps and the filtered high confidence map that corresponds to each of the plurality of phase maps. emitting light to a target object; receiving light reflected by the target object and performing sampling a number of times, to obtain a plurality of phase maps; filtering the plurality of phase maps to obtain a plurality of filtered phase maps; and forming the depth image according to the plurality of filtered phase maps; whereby filtering the plurality of phase maps comprises: obtaining an amplitude map according to the plurality of phase maps; characterised in that filtering the plurality of phase maps further comprises: obtaining a confidence map by filtering the amplitude map; and filtering the plurality of phase maps by employing a joint bilateral filtering scheme and using the confidence map as a guiding map; wherein filtering the plurality of phase maps by employing the joint bilateral filtering scheme and using the confidence map as the guiding map comprises: segmenting each of the plurality of phase maps into a low confidence map and a high confidence map according to the confidence map; and filtering the high confidence map obtained from each of the plurality of phase maps with the joint bilateral filtering scheme to obtain a filtered high confidence map, wherein each of the plurality of filtered phase maps is obtained by processing the low confidence map obtained from each of the plurality of phase maps and the filtered high confidence map that corresponds to each of the plurality of phase maps. obtaining an amplitude map according to the plurality of phase maps; characterised in that filtering the plurality of phase maps further comprises: obtaining a confidence map by filtering the amplitude map; and filtering the plurality of phase maps by employing a joint bilateral filtering scheme and using the confidence map as a guiding map; wherein filtering the plurality of phase maps by employing the joint bilateral filtering scheme and using the confidence map as the guiding map comprises: segmenting each of the plurality of phase maps into a low confidence map and a high confidence map according to the confidence map; and filtering the high confidence map obtained from each of the plurality of phase maps with the joint bilateral filtering scheme to obtain a filtered high confidence map, wherein each of the plurality of filtered phase maps is obtained by processing the low confidence map obtained from each of the plurality of phase maps and the filtered high confidence map that corresponds to each of the plurality of phase maps. segmenting each of the plurality of phase maps into a low confidence map and a high confidence map according to the confidence map; and filtering the high confidence map obtained from each of the plurality of phase maps with the joint bilateral filtering scheme to obtain a filtered high confidence map, wherein each of the plurality of filtered phase maps is obtained by processing the low confidence map obtained from each of the plurality of phase maps and the filtered high confidence map that corresponds to each of the plurality of phase maps.