The invention discloses a reactor bottom rectifier comprising a center layer (1) made of bird nest honeycomb ceramics, at least one interlayer (2) and an outer layer (3), wherein the porosities of the center layer, the interlayer and the outer layer are successively increased and the center layer, the interlayer and the outer layer are respectively arranged in a center layer conical body (6), an interlayer conical body (5) and an outer layer conical body (4) which are concentrically arranged to ensure that reticular honeycomb holes with different porosities are formed in the reactor bottom rectifier. In the invention, the reactor bottom rectifier is made of bird nest ceramics with high-density honeycomb holes; the minimum density of the high-density honeycomb holes is more than 200 meshes; the bird nest has huge pore space and dense grids as well as a structure of that porosities of bird nest honeycomb holes are successively increased from the center to the edge; when liquid raw material enters into the bottom of a reactor, the analysis time of water points formed by liquid oil on a main agent layer can be greatly enhanced and the flow distribution is more uniform to ensure that the compact and more uniform distribution of the liquid oil can be formed on the main agent layer and the influence of turbulence can be furthest eliminated; therefore, the reaction effect of the liquid oil can be enhanced and the reaction efficiency of the reactor can be enhanced.