Aiming at the problem of high density and no water control effect of conventional ceramsite proppants，the surface of the ultra-low-density organic proppant（ULDOP）matrix was oxidized at a high temperature to generate active groups on the surface，and then the nuleophilic addition reaction of the activated ULDOP and perfluorocarboxylic acid was carried out to obtained an ultra-low-density water-controlling proppant（ULDWCP）. The wettability，water resistance and oil-water phase percolation properties of the ULDWCP were evaluated，and the field application tests were carried out. The results showed that the contact angle of water on the surface of the ULDWCP reached up to 158.6°，and the water blocking height was 25 cm. Compared with before modification，the seepage flow resistance of the formation water increased by 40% ，indicating obvious selective water controlling effect，and the erosion resistance of ULDWCP was excellent. The filling rate of the ULDWCP in field test had reached up to 100%，and the water cut and the rising rate of water cut after production were far lower than those of adjacent wells，and the oil production was significantly higher than that of adjacent wells，showing a good application prospect.