The utility model relates to a novel roof rainwater collect device comprises the mouth that catchments, rainwater fill, sump pit, purification tank, storage water tank, suction pump, sets up convex trash screen in the rainwater is fought, be separated by through the barricade between sump pit and the purification tank, and the municipal pipe network of sump pit upper left side intercommunication,left side below links to each other with sewage pipe network, and the right side is passed through arc water guide mouth and is linked to each other with the purification tank, and purification tank right side intercommunication storage water tank sets up suction pump and examination room in, set up the maintenance ladder simultaneously.