Abstract: The ongoing energy revolution drives the renewable energy assuming a major role in the power market, primarily due to its low cost and low carbon characteristics. However, the volatility of renewable energy and load brings new challenges to market clearing. The increasing installed capacity of new energy units leads to a corresponding decrease in the proportion of thermal power units providing auxiliary services for new energy, prompting thermal power units to inflate the price of auxiliary services to gain market share. To promote the efficient integration and balance between new and traditional energy sources, a spot market incentive mechanism considering source-load uncertainty is proposed based on the fuzzy solution method and VCG trading mechanism. Stage 1: A fuzzy chance-constrained planning model is established with source-load uncertainty taken into account, while the tolerance of forecast risk is characterized with certain confidence level. Plausibility conclusions are then drawn by using the affiliation function for clear equivalence class processing. Stage 2: In the light of the case that the characteristic of VCG mechanism does not satisfy the revenue-expenditure balance, an expost processing strategy for peak load is proposed. The example based on the IEEE39 node system demonstrates that the VCG mechanism promotes the real offer of thermal units based on the new energy output obtained in stage 1. Moreover, the ex-post processing strategy for addressing the imbalance in revenue and expenditure under the VCG mechanism reasonably widens the peak-valley price difference. This method guides the electricity consumption behavior of market members with clear price signals and provides a fair and win-win market environment for the high proportion of new energy and thermal units to participate in spot market.