The present invention discloses a stiffness testing device for automobile seat testing, which relates to the technical field of automobile seat testing; the device comprises a base plate and an
impact component, wherein a seat base is fixedly connected above the base plate, a seat back is fixedly connected above the seat base, a marking pump and a belt support frame are fixedly connected above the base plate, stabilizing wheels and stabilizing wheel groups are rotatably connected at both ends of the belt support frame, one end of the stabilizing wheel is transmission-connected with a driving belt, and one side of the driving belt is slidably connected to the belt support frame; when the movable end of the
impact component moves, the driving rod is driven to move horizontally through a lever on one side, and the marking pump is driven to spray a straight
colored line to a rotating shaft connecting the seat back and the seat base through a spray line
assembly, and then the movable end of the
impact component hits the seat back, if the connection of the seat back is deformed, the straight line will be broken for easy inspection, and at the same time, ink can be automatically sprayed during the impact without manual line painting, so that the operation is more convenient and the safety is improved.