The invention provides an electrochemical reactor and a method for electrocatalytically removing chloride ions and relates to the technical field of wastewater treatment. The anode of the electrochemical reactor comprises a net basket made of insoluble metal and a Ru-Ti-AC catalytic material filling the net basket, and a carbon rod or a metal wire is led out of the middle of the anode and connected to the positive pole of a power supply; a cathode comprises multiple metal plates or metal nets arranged at intervals, the interval between every two adjacent metal plates or metal nets is 4-6 cm, and the cathode is connected to the negative pole of the power supply through a wire. The electrochemical reactor is high in electrolytic efficiency and high in chloride ion degradation rate. The method for electrocatalytically removing the chloride ions is implemented with adoption of the electrochemical reactor. To-be-treated wastewater is introduced into a reaction tank of the electrochemical reactor and submerges the anode and the cathode, constant current is applied between the anode and the cathode, the wastewater is stirred continuously, and a reaction is performed for 0.1-2 h. The method is convenient to operate and beneficial to large-scale industrial application.