In this work, quicklime blended recycled plaster materials (R-LP) were prepared to find out their hydration and mechanical properties. The results show that the setting time of R-LP was shortened due to the increasing of Ca²⁺ in the saturated solution in regard to the Ca²⁺ and SO4²⁻ ions. Also, the strength of R-LP was substantially decreased as well. Correspondingly, the hydration and strength ... [Show full abstract] of plaster of Paris with quicklime (POLP) were slightly delayed and increased, respectively. The strength development analysis shows that Ca(OH)2 and CaCO3 fill pores in the pastes, which increases the strength of POLP. While Ca(OH)2 and CaCO3 have no bonding force in R-LP and interweave closely with gypsum into compounds, which weakens their close overlapping of gypsum, thus achieving low-strength R-LP. Therefore, different hydration and mechanical property development could be seen in POLP and R-LP. In principle, these findings will lay a solid ground work for the utilization of recycled plaster.