Horizontal polar plate multi-dimensional electrode electrocatalysis reactor wastewater treatment equipment comprises a shell, a cathode plate and an anode plate which are relatively parallel, a particle electrode filled between the cathode plate and the anode plate, a water distributor, a water inlet pipe, an aerator, an air inlet pipe, an effluent weir trough, a water outlet pipe and a power supply; the cathode plate and the anode plate are respectively connected with the cathode and the anode of the power supply; a plurality of through holes are distributed on the cathode plate and the anode plate which are horizontally positioned in the shell of the equipment; the water distributor, the water inlet pipe, the aerator and the air inlet pipe are positioned at the lower part of the shell of the equipment; and the effluent weir trough and the water outlet pipe are arranged at the upper part of the shell of the equipment. After being evenly distributed by the water distributor, the wastewater flows across a reactor from bottom to top; the horizontal polar plate structure design not only avoids the short circuit of water flow and improves the mass transfer effect, but also ensures that the wastewater can alternatively flow across the cathode plate and the anode plate and the oxidation reaction of the anode plate and the reduction reaction of the cathode plate coexist in a system, and causes different organic pollutants in wastewater which can be degraded by the oxidation reaction and the reduction reaction to be degraded and treated.