The release of heavy metal(loid)s (HMs) in lake sediments is highly sensitive to environmental conditions, and understanding its release process and influence mechanism is crucial for managing ecological risk in lakes. This study took Bosten Lake as a typical representative and integrated the methodological and technical system of passive sampling technology / DIFS model / Bayesian network model to analyze the process and influence mechanism of HMs release in the core microscopic system of lake overlying water - porewater - sediment core, and comparatively discussed the characteristics of HMs release in lake sediments in arid areas. In the surface sediments of Bosten Lake, Cr and Ni can reach a supply balance, with other elements continuously supplied from the solid to the liquid phases at different rates depending on the sampling areas. Cd posed the greatest potential ecological risk (RAC > 30, RSP > 3), and Zn had the greatest potential toxicity to aquatic organisms (RQ > 28.59), and the estuary area requires the most attention. The cation exchange in the overlying water and the adsorption/desorption properties of Fe and total organic carbon (TOC) in the sediments jointly controlled the 'reactivation' ability of HMs due to the saltwater characteristics of the overlying water in lakes in arid areas. These findings have promoted the understanding of the diffusion mechanism of HMs release from lake sediments in arid areas and provided references and support for the formulation of control strategies for endogenous metals pollution in these sediments.