The invention discloses an environmental monitoring deepwater sampler. The environmental monitoring deepwater sampler comprises a main body box and a water pump storage box, a rotating cylinder is rotatably mounted in the main body box by a rotating shaft, one end of the rotating shaft goes through the inner wall of the main body box and is provided with a rotating handle, a water tube is wound around the rotating cylinder by a winding plate, an electric connecting wire is fixed on the surface of the water tube, a measuring scale is arranged on the surface of the water tube, a notch is arranged in the upper end surface of the water pump storage box, a rotating wheel is rotatably mounted at the notch, a water pump is stored in the water pump storage box, a second side opening door is rotatably mounted in the outer surface of the water pump storage box, a water sample receiving container is placed in the main body box, a water capacity scale is engraved on the outer surface of the watersample receiving container, a lifting handle is mounted at the upper end of the water sample receiving container, and a first side opening door is rotatably mounted in the end surface, positioned at one side of the water sample receiving container, of the main body box. The environmental monitoring deepwater sampler has the advantages of realization of water depth positioning and sampling of a water sample, simple structure, small size and portability.