Another neutral beam injector (NBI-2) was added for the KSTAR plasma experiments, recently. It requires a deuterium gas cryo-condensation system with the pumping speeds over one million liter/sec. For this purpose, many cryo-panels and a liquid helium cryogenic system were designed and constructed take into accounting the previous NBI. After the independent performance tests of the NBI-2, it was connected to the KTSAR tokamak and applied in the plasma experiments in 2018. Details of the development results including engineering design, construction, and operation will be reported in this paper and presentation.