The present invention relates to the fields of medicinal chemistry and pharmacotherapy, and specifically relates to the chemical compound of formula (I), and its racemate, R-isomer, S-isomer, pharmaceutically acceptable salt, and mixtures thereof, as well as its method for preparation, a pharmaceutical composition containing said chemical compound, and use as a lysine-specific demethylase 1 (LSD 1) inhibitor. The cyclopropylamine chemical compound to which the present invention relates may be used in the treatment of cancer.
