2D transition metal dichalcogenides (TMDs) have significant research interests in various novel applications due to their intriguing physicochemical properties. Notably, one of the 2D TMDs, SnS , has superior chemiresistive sensing properties, including a planar crystal structure, a large surface-to-volume ratio, and a low electronic noise. However, the long-term stability of SnS in humid conditions remains a critical shortcoming towards a significant degradation of sensitivity. Herein, it is demonstrated that the subsequent self-assembly of zeolite imidazolate framework (ZIF-8) can be achieved in situ growing on SnS nanoflakes as the homogeneous porous materials. ZIF-8 layer on SnS allows the selective diffusion of target gas species, while effectively preventing the SnS from severe oxidative degradation. Molecular modeling such as molecular dynamic simulation and DFT calculation, further supports the mechanism of sensing stability and selectivity. From the results, the in situ grown ZIF-8 porous membrane on 2D materials corroborates the generalizable strategy for durable and reliable high-performance electronic applications of 2D materials.