Abstract: During the operation of nuclear power plant waste activated carbon saturated with boron water is produced, and it is needed to be treated by solidification process. Activated carbon is saturated with 2.5‰ concentration(mass fraction) of boron water until a steady state is achieved to get the mock waste item. After water is dissociated from the activated carbon, then the mock waste item is threated by outside barrel solidification process with cement. The test result is steady and the solidification process program is reliable, additionally by this test it is proved that the new waste source term activated carbon can be properly treated by this technology. The conserving cement solidified form is tested according to GB 14569-1-2011, and the requirements of dissociative liquid component, mechanical property, water resistance, freezing-thawing resistance, and γ radiation resistance are satisfied. Active carbon particles in the solidified form are uniformly distributed, no uprising exist, the fluidity after mixing even 30 minutes later remain larger than 200 mm, the requirement of stability and reliability of outside barrel solidification process with cement is satisfied and verified.