The invention discloses a tumor sampling device. The tumor sampling device comprises a shell assembly, a sampling assembly and a collection assembly; the shell assembly comprises a protective cylinder, a guide tube and a gim peg, the gim peg is arranged on the right side of the protective cylinder, the protective cylinder and the gim peg are fixedly connected in a screwed mode, the guide tube is arranged on the right side of the gim peg; when the tumor cells are sampled in the sample, by spinning a rod holder, a screw rod is driven to turn, and a piston is made to move at a constant speed in apiston pipe, at the moment, negative pressure is produced inside the piston tube, accordingly the tumor cells are inhaled at a constant speed into the piston tube, the possibility of tumor cell damage caused by excessive negative pressure is avoided; in the collection of tumor cells, through a circular through hole in the piston tube, it is convenient that the tumor cells inside the piston tube are imported into an accumulator, after collection, through knobbing the accumulator, the accumulator is removed from the piston tube, and it is convenient for staff to analyze tumor cells.