Synthesis of color-tunable ultralong room temperature phosphorescence (RTP) crystals with multilevel stimuli-responsive properties is highly desirable due to their tremendous application prospects but has rarely been explored. Herein, a 2D organic–inorganic metal-halide hybrid (ABACdCl) has been originally designed and synthesized with efficient blue fluorescence and green RTP through Cd induced heavy atom effect. Due to the improved intermolecular interactions and enhanced light absorption, a high RTP efficiency up to 34% is achieved in ABACdCl With ABACdCl as a prototype, Mn-doping strategy is successfully employed to construct multicomponent RTP material with wide-tunable RTP property in response to multilevel external stimulus such as time, temperature and light. More importantly, Mn pairs are formed in Mn-doped ABACdCl, which are observed in 2D metal-halide hybrids for the first time. Due to the thermal assisted energy transfer from triplet excitons (organic unit) to Mn pairs, and the thermally activated emission from Mn pairs, tunable RTP colors between 270 and 333 K are easily realized, showing the highest sensitivity against temperature reported so far. By virtue of the above advantages, such materials are successfully applied in multilevel information storage and temperature sensors. The work promotes the development of multi-stimuli responsive RTP systems based on hybrid metal halides.