Chemical enterprises demand a large number of power load,the use of centralized power supply mode from substation need a large number of cables. By analyzing the characteristics of cable laying modes, the reasonable cable laying ways were selected in order to help reduce the investment of project and construction quantity,and at the same time it is easy for post maintenance, increase and replacement of the cable. Based on the specific circumstances of a petroleum refining enterprise's expansion design and renovation in Hebei province,the general principles of cable laying mode selection is put forward,that is chemical plant, especially large and medium-sized plant,when more cables are increased and replaced at the last stage, cable tray as the main laying mode combined with other laying modes (direct burialcable and cable trench etc.) should be adopted in plant cable laying.