Addressing the overcapacity and deficiency of effective demand caused by rapid technological development, this paper proposes an Stochastic Iterative Universal Basic Income (SI-UBI) framework. By introducing high-entropy stochastic factors in the spatiotemporal dimensions, this mechanism achieves systematic optimization in three aspects: 1. Micro-game level: By utilizing stochastic distribution, it transforms impulsive purchasing power shocks into a smoothed statistical steady state, eliminating the incentive for merchants to raise prices synchronously from a game-theoretic perspective; 2. Labor and consumption market level: randomized issuance ensures that UBI is identified as "transitory income," thereby activating the marginal propensity to consume by the lottery effect without weakening the labor force participation rate; 3. Macro-control level: Through an iterative feedback algorithm based on tax increments, it achieves the automated recovery and precision injection of currency.Further analysis also indicates that the inflation triggered by monetary stimulus is inversely proportional to its injection variance. This framework can accurately anchor the productivity dividends of the era of deep automation, providing a theoretical path for constructing a sustainable market system.