The present invention relates to the technical field of pharmaceuticals. Specifically, the present invention relates to a halo-allylamine compound, or a pharmaceutically acceptable salt, an ester, a stereoisomer or a tautomer thereof, and a pharmaceutical formulation and a pharmaceutical composition comprising the compounds, and use in preventing and/or treating a disease related to or mediated by the SSAO/VAP-1 protein,
wherein R1, R2, R3, R4, R5, R6, L1 and Cy1 are defined in the specification.