In this paper

a kind of fast algorithm for the steady temperature rise of tunnel cable groups with the aim of improving calculation efficiency of steady temperature rise of tunnel cables and supporting operator’s real-time load adjustment.Firstly

a single piece of cable is taken as an example

the quantitative law of "convention heat dissipation-convection thermal resistance-in the tunnel is proposed throughout the analysis of definite element calculation result of multiple condition steady temperature rise and

on this basis

the corresponding fast algorithm is proposed.Then

the algorithm is expanded to be applicable for the multiple pieces of cables and the cable with triple-circuit vertical layout is verified as an example.It is shown by the verification result that the fast algorithm proposed in this paper is simple and accurate

can meet operation need and create conditions for the study of fast algorithm of subsequent transient temperature rise.