Abstract: The in-situ utilization of lunar water-ice resources constitutes a fundamental technological bottleneck for enabling sustainable future deep space exploration. The transmission probability of gas transport following water-ice acquisition from lunar regolith is a critical determinant of overall system performance for in-situ water extraction devices. This study developed a three-dimensional numerical simulation model of a lunar regolith water extraction device based on the Monte Carlo method. Using professional simulation software, a systematic investigation was conducted to examine the influence mechanisms and underlying principles of key parameters—including device wall temperature, solenoid valve interface dimensions （size and height）, and bottom irradiation area—on the transport probability of water molecules. The results indicate several key relationships. Across the temperature range of 183.2 K to 483.2 K, the transport probability of water molecules increases with higher device wall temperatures, but the rate of increase progressively attenuates. An increase in the solenoid valve interface height was found to significantly inhibit transport probability, while an increase in interface size enhanced it. Furthermore, the bottom irradiation area exerts a strong non-linear regulatory effect on transport probability. A critical transition was observed when the radius of the irradiation area expanded to equal the device's radius of 0.4 meters, at which point the transport probability exhibited a sharp, abrupt increase. This study elucidates the dominant factors and their operative mechanisms governing water vapor transport within the simulated lunar regolith environment. It clarifies the complex transport dynamics arising from the coupling of multiple parameters. The findings provide essential theoretical support and specific technical direction for subsequent phases, including ground-based experimental validation, iterative structural refinement of the extraction device, and the optimized design of high-efficiency systems for in-situ lunar water resource utilization. Specifically, the quantified parameter thresholds and identified non-linear relationships establish a basis for balancing thermal control, structural configuration, and energy input to maximize extraction yield—a crucial consideration for developing practical and energy-efficient systems capable of operating under the severe constraints of the lunar environment.