The invention discloses a chemical wastewater residual chlorine emission reduction device which comprises a residual chlorine emission reducer, wherein a cavity is formed in the residual chlorine emission reducer; a baffle plate is welded to the side wall of the cavity; a mounting hole is formed in the inner wall of one side of the cavity; a bearing plate is moveably mounted inside the mounting hole; a holding groove is formed in the top of the bearing plate; activated carbon is placed in the holding groove; a support plate is welded on one side of the residual chlorine emission reducer; a clamping column groove is formed in the bottom of the bearing plate; a clamping column is mounted inside the clamping column groove in a sliding manner; a clamping groove matched with the clamping columnis formed in the inner wall of the bottom of the mounting hole; the clamping column is clamped with the clamping groove; a sliding hole is formed in the inner wall of one side of the clamping columngroove; a winding wheel is rotationally mounted inside the clamping column groove. The device is good in practicability, simple in structure and convenient to operate, the bearing plate can be conveniently released from fixation, in addition, the activated carbon can be conveniently moved to the outer side of the residual chlorine emission reducer, then a worker can clean or replace the activatedcarbon conveniently, and convenience can be brought to people to use the device.