In view of the increasing number of cable channels in substation and the large number of cables distribution, the fault of a certain line will bring great security hazard. A design scheme of multi- parameter acquisition and early warning system for cable channel in substation is proposed in this paper, focusing on the temperature field and current carrying capacity of power cable. Through the finite element analysis software, the geometric model of 10 kV single core cable four-loop standard laying cable trench is established, and the steady-state ampacity is calculated by secant method. The temperature field and current carrying capacity under different working conditions are analyzed by experiments. The results show that for on-line cables temperature monitoring, only the cable with the highest temperature is needed to be monitored, and if the cable laying density is too high, the current carrying capacity of the cable will decrease. The research provides some reference for the development of multi-parameter acquisition and early warning technology of substation cable channel in China.