The invention provides a cupping jar and belongs to the technical field of medical equipment. The problem that operation of an existing cupping jar is troublesome is solved. The cupping jar comprises a jar body with the open lower end. A piston is in sliding connection with the interior of the jar body. The outer edge of the piston abuts against the inner wall of the jar body. The center of the end face of the jar body is provided with a guide hole. A pull rod is in sliding plugged connection with the interior of the guide hole. The inner end of the pull rod is connected with the upper end face of the piston. The pull rod is provided with a positioning block which can fix the pull rod when the piston moves upwards. The pull rod is further provided with an adjusting piece which can adjust the vacuum degree in the jar body after the pull rod is fixed. According to the cupping jar, operation is convenient, the vacuum degree inside the cupping jar can be adjusted, and use is more flexible.