The invention discloses a medium voltage electric penetration assembly with a thermocouple temperature measuring assembly. The electric penetration assembly comprises three medium voltage power conductors and further comprises an E-shaped twin thermocouple assembly used for measuring insulation material surface temperature of at least one medium voltage power conductor. The E-shaped twin thermocouple assembly can monitor the insulation surface temperature of the conductor in a barrel in real time and transmit the signals for a long distance. The added thermocouple cable does not affect electric performance and air tightness of the medium voltage penetration assembly. The use temperature of the E-shaped thermocouple is -200-900 DEG C, the sensitivity is high, and the electric penetration assembly is used for measuring tiny temperature change.