<p>Hydrological connectivity in tidal creek systems is a fundamental element of coastal wetland ecosystems, influencing the interactions among various key ecological factors within the wetlands. Understanding the mechanisms by which hydrological connectivity affects the functional feeding groups (FFGs) of macrobenthos is crucial for the restoration and maintenance of wetland ecosystems and biodiversity. This study focuses on a typical tidal creek system in the Yellow River Delta, where we investigated macrobenthos, environmental factors, and metal elements across different seasons in tidal creek areas. The results indicated that the distribution of most metal elements showed significant differences across different tidal creek levels (<i>P</i> &lt; 0.05), with metal concentrations decreasing as hydrological connectivity increased. Tidal creeks with greater differences in hydrological connectivity exhibited lower chemical connectivity. SCs accounted for the highest proportion of abundance in the tidal creek system, reaching 40.9%, while GCs were the keystone functional feeding group (KFFG) that maintained the stability of macrobenthic communities (KFFG score = 2.25). The study further demonstrated that as hydrological connectivity strengthened, the structure of the co-occurrence network became more complex. These results emphasized the critical role of hydrological connectivity in driving the complexity of macrobenthic co-occurrence networks in typical tidal creeks. Total organic carbon (TOC), silicate (SiO₃-Si), ammonia nitrogen (NH₄-N), and metal element concentrations in sediments were the key environmental factors influencing the FFG structure in different tidal creek levels. The analysis of ecosystem functional attributes indicated that higher hydrological connectivity contributed to maintaining the productivity and ecological stability of the tidal creek system.</p>