Surface sediments, as the source and sink of heavy metals in polluted water, are easy to enrich and release heavy metals in water environment. In fact, the water of Hequ section of the Yellow River was polluted by Pb and Cr. In this paper, the adsorption and desorption characteristics of Pb(Ⅱ) and Cr(Ⅵ) onto the surface sediments of Hequ section of the Yellow River were investigated by using inductively coupled plasma mass spectrometry (ICP-MS) under the optimized experimental conditions. The results showed that the sediments had strong adsorption effects to Pb(Ⅱ) and Cr(Ⅵ) with endothermic and spontaneous process (ΔG<0, ΔH>0) with the adsorption rates reaching more than 98% in the initial 5 min. Kinetic experiments showed that the adsorptions of Pb(Ⅱ) and Cr(Ⅵ) were in accordance with the pseudo-second-order kinetics. The isothermal adsorption equations revealed that the adsorption of Pb(Ⅱ) was consistent with the Langmuir model, while the adsorption of Cr(Ⅵ) followed the Freundlich model. The desorption processes kept to the Elovich equation, which was influenced chiefly by pH. The competitive adsorption of Pb(Ⅱ) and Cr(Ⅵ) showed that the adsorption rate of Pb(Ⅱ) was greater than that of Cr(Ⅵ), while both of them were lower than the single ion adsorption rate. Scanning electron microscopy (SEM), pore size and specific surface area analysis showed that the sediments of Hequ section of the Yellow River had an irregular surface structure and a relatively high specific surface area. This paper displayed the adsorption-desorption behaviors of Pb(Ⅱ) and Cr(Ⅵ) onto the sediments of Hequ section of the Yellow River, which has guiding significance for sediment pollution assessment, pollution remediation and mastering the mechanism of heavy metals onto the sediments.