Heat treatment method of unidirectionally-warped and bent-downwards steel plate

The invention discloses a heat treatment method of a unidirectionally-warped and bent-downwards steel plate, which comprises the following steps of: manufacturing a group of lantern rings according to the size of the last roller way of charging roller ways of a heat treatment furnace, wherein the inner diameter of each lantern ring is matched with the outer diameter of the last roller way of the charging roller ways of the heat treatment furnace, each lantern ring comprises an upper ring and a lower ring, upper ring installation holes are arranged at two lateral end parts of the upper ring, and lower ring installation ring matched with the upper ring installation holes are arranged at two lateral end parts of the lower ring; when a steel plate with the thickness below 10mm is subjected to heat treatment, uniformly installing 3-5 groups of lantern rings on the last roller way of the charging roller ways to realize charging of the unidirectionally-warped and bent-downwards steel plate and finish the heat treatm