Disclosed is a method for coding and decoding depth information, and the method includes: data in original Depth Look-up Tables (DLTs) of selected views are combined to establish a unified DLT, a value of the number of elements in the unified DLT and each element in the unified DLT are coded respectively and a coded value and each coded element are transmitted to a decoder; and depth information of each view is coded by taking the unified DLT as a whole or in portions and coded depth information of each view is transmitted to the decoder. Further disclosed are a system and device for coding and decoding depth information; by means of the disclosure, it is possible to reduce redundancy of coding information and improve coding and decoding efficiency.