The invention belongs to a testing technique for fire-resisting materials, and provides a refractoriness automatic tester for horizontal imaging. The refractoriness automatic tester is provided with an observation hole which is communicated with a test chamber of a tester furnace body and is arranged horizontally, a camera connected with a computer is arranged outside the observation hole, and a cone plate (4) is arranged in the test chamber and is positioned between a heating element (8) and the observation hole; a plurality of cones are upright on the cone plate and are arranged in rows, the central lines of the cones are positioned on the same plane, and an intersecting line of the plane and the upper surface of the cone plate is vertical to the primary optic axis of the camera. When the refractoriness automatic tester is used for testing, the cone plate (4) and the cones (5) are in a static state, the camera can clearly shoot bent inverted images of all the cones simultaneously, the bent inverted images are displayed by a display connected with the computer, and the computer records the temperature of the cones when the cones are bent and inverted. With the mode and the structure, the plurality of the cones can be measured simultaneously in each test, the heat preservation effect of the furnace body is good, the testing efficiency is improved, the energy source is saved, and simultaneously the photographing and displaying effects are more perfect.