High-degree connectivity of clusters in open-framework chalcogenide semiconductors conceptually facilitates electron mobility between clusters; however, no direct evidence was obtained to prove the prediction because of the shortage of suitable structure models among such systems. Herein, two open-framework chalcogenides built from the same types of heterometallic P2-CuInSnS clusters but with different spatial connectivities of clusters were obtained, in which 3-connected clusters are assembled into a 3D framework with SrSi2 topology (MCOF-1) and 4-connected clusters ( 4-P2) are arranged into diamond topology (MCOF-2). Compared to MCOF-1, MCOF-2 exhibits a relatively rapid photocurrent response, good reproducibility, and high electrocatalytic oxygen reduction reaction activity. This work substantially demonstrates that cluster-based chalcogenide frameworks with higher-degree cluster connectivity possess faster electron-transport efficiency between adjacent clusters relative to low-connected ones with the same building units.