Abstract: The tank container for intermediate level liquid waste (ILW) is a package type device, which has the functions of receiving, transportation and temporary storage for ILW. The vacuum, pressure, liquid level monitoring, leakage alarm, off-gas purification, stir and programmable logic controller systems were equipped in the device. Loading and unloading of ILW were realized through vacuum system. The primary design of the system was analyzed and some shortcomings were referred in this paper. The interface system, loading/unloading and flushing system, and the tractor system were improved and verified through test. The test results show that the tank container system after improved can well meet the requirement of China Institute of Atomic Energy.