Local freezing construction method for joint waterproofing of underground diaphragm wall

The invention discloses a local freezing construction method for underground diaphragm wall joint waterproofing, which comprises the following steps of: after an underground diaphragm wall groove section is excavated, arranging a micro-channel heat exchange plate in a joint of the underground diaphragm wall groove section, and simultaneously putting the micro-channel heat exchange plate into the groove section along with an underground diaphragm wall reinforcement cage; after groove section concrete is poured, the micro-channel heat exchange plate serves as a part of the underground diaphragm wall and is permanently arranged in the wall body; after concrete of the diaphragm wall is poured, all the joints are grouped according to the environment of a building around the positions where the joints are located and the ground surface deformation control level, the pre-freezing range of the joints of the diaphragm wall is determined, and micro-channel heat exchange plates in the pre-freezing range and a ground fre