The invention discloses a gas-liquid-solid multiphase flow reactor and a filter arrangement method thereof. The gas-liquid-solid multiphase flow reactor comprises a reactor body (1) and a filter (2) located in the reactor body (1). The reactor is characterized in that the filter (2) includes a plurality of filtration components (21) arranged in a circle along the circumferential direction, wherein the center of each filtration component (21) avoids areas with slow slurry flow rate. During filter arrangement, the invention gives consideration to the slurry flow rate, solid holdup and other hydrodynamic factors in the filter body, as areas with slow slurry flow rate are avoided, a filter cake formed on the filter adopting cross flow filtration can be flushed timely without rapid thickening, also by avoiding the high solid holdup areas, rapid filter cake thickening can also be avoided, thus increasing the filtration capacity and stable filtration time of the filter, and the filtration performance of the filter can be improved significantly.