<p>The simulated hydraulic fracturing experiments revealed that microfractures accounted for a relatively high fracture surface density, approximately two-thirds of the total fracture surface area, with an average fracture width of 0.245 mm. These microfractures constitute a critical component of the volumetric fracture network that develops in shale gas wells after hydraulic fracturing. The fracture conductivity tests under unsupported conditions indicated that both shear-slip and open-type microfractures exhibited limited conductivity under high closure stress, falling short of the optimal level required for effective gas-well stimulation. This observation was consistent with the rapid decline in post-fracturing production and confirmed that the low long-term conductivity of microfracture systems constrains the gas-supply capacity of wells. To address this limitation, the use of fine-grained proppants (typically &lt; 300 μm) was proposed to mitigate the stress sensitivity of microfractures, reduce mechanical damage, and enhance fracture conductivity. Experimental results demonstrated that micro-proppants effectively preserved microfracture conductivity under high closure stress; however, the conductivity was highly dependent on proppant concentration. An optimal placement concentration was identified, reflecting the transition in the dominant role of micro-proppants within microfractures, from propping at low concentrations to plugging when excessive. Excessive proppant loadings increased fracture spacing but reduced the effective seepage area, leading to diminished flow capacity. Consequently, an optimal micro-proppant placement concentration was determined to ensure the long-term retention of high conductivity. In this study, the optimal value was 0.078 kg/m2 for microfractures with an average width of 0.261 mm under high closure stress. These findings provide valuable guidance for optimizing proppant design and enhancing fracture reconstruction efficiency in shale gas reservoirs.</p>