[Objective] The effects of water content and molecular weight of polyacrylamide (PAM) on shear strength of reconstructed iron tailing sand were analyzed in order to better understand slope stability and ecological restoration of mining areas. [Methods] An indoor shear strength experiment was conducted by reconstructing iron tailing sand. Five reconstruction soil mixing rate treatments of soil (S) and tailings (T) were established: S (0% T), S₃T₁ (25% T), S₁T₁ (50% T), S₁T₃ (75% T) and T (100% T). Treatments also included two water contents (15%, 20%), two molecular weights of PAM (3.00×10⁶ , 6.00×10⁶ Da), and three compaction states (loose, tight, and dense) for each reconstruction pattern. [Results] ① Under the same compaction state, the internal friction angle, cohesion, and shear strength for the five reconstruction patterns all decreased with increasing water content. ② Under the same water content, the internal friction angle, cohesion, and shear strength of the five reconstruction patterns increased with increasing compaction. ③ Addition of PAM effectively improved the shear strength of reconstructed iron tailing sand, and shear strength decreased with increasing molecular weight of PAM. ④ When PAM with a molecular weight of 3.00×10⁶ Da was added into the five reconstruction patterns, the shear strength and water infiltration capacity of S₃T₁ were greater than for the other reconstruction patterns. [Conclusion] The reconstruction pattern of S₃T₁ with a water content of 15% and PAM molecular weight of 3.00×10⁶ Da were conducive to the restoration of the ecological environment in mining areas and to the improvement of the stability of iron tailing sand.