Abstract: A use of micro- and nano-MgH2 compound particles in the inhibition of Leishmania infection and in the treatment of Leishmaniasis is provided. The micro- and nano-MgH2 compound particles can be used to prepare a pharmaceutical composition for inhibiting Leishmania or to prepare a pharmaceutical composition for treating a skin or mucosal ulcer or visceral damage caused by Leishmania infection. The present disclosure discovers for the first time that the micro- and nano-MgH2 compound particles can significantly reduce the number of Leishmania in macrophages and inhibit the proliferation of Leishmania, indicating a very prominent insecticidal inhibition effect. The micro- and nano-MgH2 compound particles of the present disclosure can quickly and effectively cure a skin ulcer and/or a mucosal ulcer caused by Leishmania and an impaired function of an internal organ (mainly liver and spleen) caused by Leishmania and have high biosafety and huge clinical application values.