investigate the dependence between the temperature field distribution and ampacity of submarine umbilical cables and improving the reliability of operation，the finite element method was used in this paper to solve the limitation of traditional thermal circuit analytical method． The software of ANSYS was used to analyze the sub-marine umbilical cables models with complex structure，and results of the whole temperature field distribution wereshown in the paper． Finally，the most appropriate configuration of umbilical cable is decided by comparing the difference of temperature field distribution in different cables，and by comparing the effect of different insulating and sheath materials on distribution of temperature field and ampacity of umbilical cable．