The emerging of molecular spintronics offers a unique chance for the design of molecular devices with different spin-state, and the control of spin-state becomes essential for molecular spin switches. However, the intrinsic spin switching from low-spin to high-spin state is a temperature-dependent process with a small energy barrier that low temperature is required to maintain the low-spin state, and thus the room-temperature operation of single-molecule devices have not yet been achieved. Here, we investigated the single-molecule charge transport through a diamagnetic square planar nickel(II) porphyrin using the scanning tunneling microscope break-junction (STM-BJ) technique. The reversible single-molecule conductance switches are demonstrated by utilizing a coordination-induced spin-state switching to manipulate the spin state between S = 0 and S = 1 at room temperature. Furthermore, the different coordinated complexes could be distinguished from the conductance traces, which cannot be realized by the ensemble investigations such as NMR and UV-vis spectrums. The combined DFT calculations revealed that the conductance changes come from the different spin-states of the molecules varying the number of coordination ligands, suggesting coordination-induced spin-state switching provides a new way towards room-temperature molecular spintronics.