The invention relates to a testing 
system for deep soil freezing / thawing process, which is structurally characterized in that a temperature-controlled box is connected with an external cold bath; a 
high pressure-resistant 
organic glass cylinder is arranged on a temperature-controllable steel base; two small holes are formed in the base, one is connected with a water guide 
pipe, and the other is connected with a pressure adjusting 
pipe; a permeable stone, a piece of 
filter paper and a sample are sequentially arranged at the upper part of the lower base, and a temperature sensor is mounted in the sample; a temperature-controllable upper press head is arranged at the upper part of the sample; a line leading-out hole is formed in the upper press head, and is sealed through 
sealant after the line is lead out; the upper press head is connected with the transmission rod of a testing 
machine; a measuring cylinder is connected with the sample through the water guide 
pipe; and the measuring cylinder is arranged on a weighing sensor and fixed through a bracket. By adopting the testing 
system, the freezing / thawing process of the deep soil can be rather systematically researched, so as to obtain the 
frost heaving rate and the water absorbing / draining rate of the deep soil which is in different depths frozen under the different temperature gradients. The testing 
system provides the technical guarantee for the research in clarifying the action of the external load on the 
forming processes of the freezing soil and the frozen soil cold-formed structures, and the mutual action of the temperature, the 
moisture content and the pressure of the soil body in the process of freezing under the high-
pressure action.