Mixed gas gas-liquid phase equilibrium transformation detection box with double-cavity structure

The invention discloses a mixed gas gas-liquid phase equilibrium transformation detection box with a double-cavity structure, which comprises a vacuum cavity and a sample cell, the sample cell is arranged in the vacuum cavity, a gap is arranged between the outer wall of the sample cell and the inner wall of the vacuum cavity, the sample cell is provided with a first observation window capable of observing the inner cavity of the sample cell, and the first observation window is provided with a second observation window capable of observing the inner cavity of the sample cell. The vacuum cavity is provided with a second observation window corresponding to the first observation window in position. The sample cell has the advantages that the vacuum cavity is used as a heat preservation cavity of the sample cell, the sample cell is not in direct contact with the vacuum cavity, and after the vacuum cavity is vacuumized, heat exchange between the interior of the vacuum cavity and the outside can be regarded to be ba