Disclosed are methods and devices for coding and decoding depth information, which relate to a Three-Dimensional Video (3DV) coding technology. The coding method includes: arranging all elements in a DLT in an ascending order of values, wherein the DLT is a data structure representing depth numerical values by index numbers; coding a value of a first element in the DLT, and writing the bits of the value into a bitstream; and coding a difference value between a value of each of the other elements except the first element in the DLT and a value of an element with an index number smaller than an index number of the each of other elements in the DLT respectively, and writing the value of the difference value into the bitstream. The method for decoding depth information and related coding and decoding devices are also provided. By the technical solutions of the disclosure, efficiency of coding and decoding depth information is improved, and resource occupation during depth information coding is reduced.