The invention discloses a slurry overflow prevention clamping slot type cylindrical formwork plate and a construction method and belongs to the technical field of building cylindrical formwork plates.The slurry overflow prevention clamping slot type cylindrical formwork plate at least comprises two circular arc formwork plate bodies, first connecting parts are fixedly connected to the two ends ofthe two circular arc formwork plate bodies, first connecting holes are formed in the first connecting parts, reinforcing rib plates and connecting steel plates are fixedly connected to the outer walls of the two circular arc formwork plate bodies, second connecting parts are fixedly connected to the two ends of one circular arc formwork plate body, second connecting holes, positioning grooves andflow blocking grooves are formed in the two second connecting parts, third connecting parts are fixedly connected to the two ends of one circular arc formwork plate body, third connecting holes, positioning parts and flow blocking parts are arranged on the two third connecting parts, fourth connecting parts are connected in the third connecting holes and the corresponding second connecting holesin a matched mode, the positioning parts are matched with the positioning grooves, the flow blocking parts are matched with the flow blocking grooves, slurry overflowing and leaking at joints of cylindrical formwork plates can be effectively prevented in concrete construction, and meanwhile the perpendicularity of concrete and the construction quality can be ensured.