Underground nuclear plant with nuclear island cavern groups distributed in L shape

The invention discloses an underground nuclear plant with nuclear island cavern groups distributed in an L shape. The underground nuclear plant comprises nuclear islands used for generating steam through nuclear fission energy and arranged in underground cavern groups, a reactor factory building cavern used for containing reactor factory buildings is arranged in the middle in the underground cavern groups, and auxiliary cavern groups used for containing auxiliary factory buildings are arranged around the reactor factory building cavern in an L shape. By means of the underground nuclear plant with the nuclear island cavern groups distributed in the L shape, an existing underground cavern digging technology meets the building requirement of the underground nuclear plant, the number of caverns contained in the auxiliary cavern groups is small, and stability of surrounding rock is facilitated.