The invention discloses a VPCE system allowing automatic monitoring sampling analysis and a process thereof. The VPCE system includes a tritium-contained water vapor generation device, a vortex shedding flowmeter, a product water collection device, a lower condensation column, a hydrogen generation device, a hydrogen mass flow controller, a first catalytic exchange column, a second catalytic exchange column, a third catalytic exchange column, a fourth catalytic exchange column, a fifth catalytic exchange column, heating isolating layers, an upper condensation column, a tritium-contained hydrogen dryer, a tritium-contained hydrogen mass flow controller, a gas storage device, a refrigerating unit, a molecular sieve drying device, and a chromatographic analyzer. The process includes: a, filling catalyst in the catalytic exchange columns; b, starting a tritium-contained hydrogen collecting system; c, preheating the catalytic exchange columns to the temperature of 200 DEG C; d, injecting hydrogen into the catalytic exchange columns; e, injecting vapor to the catalytic exchange columns to perform exchange reaction and staring a sampling detection system at the same time; and f, staring a condensation system. The VPCE system allowing automatic monitoring sampling analysis and the process thereof can solve the problem that the prior art is low in automatic level and exists energy waste.