The utility model discloses a sampling device suitable for petroleum with different densities. The sampling device comprises a filter screen cylinder, a sliding rod, a sliding ring, a threaded connecting pipe, an exhaust pipe, a connecting handle, a lock catch, an oil inlet, a scraping piece, a rubber plug, an integral shell, a connecting rod, a cover body, a crank, a winding cylinder I, a windingcylinder II, a safety rope, a scale rope, a limiting plate, a rotating shaft, a weight-increasing block, a weight box and an oil outlet pipe. According to the utility model, the plurality of weight increasing boxes are arranged on the outer side wall of the integral shell of the sampling device; The weight of the sampling device can be conveniently adjusted and increased by arranging the weight increasing box and placing the whole blocks of different sizes in the weight increasing box, so that the sampling device can sink in petroleum of different densities, the lowest layer of the petroleumcapable of sinking by the sampling device can be realized, and petroleum samples of different depth layers of the petroleum can be sampled in batches.