The invention relates to a type of high-
toughness alloy steel, and a heat treatment device thereof. The material is a 25CrMnSi material. The heat treatment device comprises orderly arranged components of: a normalizing furnace in which a temperature can be configured as 920 DEG C +-10 DEG C, and a
residence time can be configured as 120 minutes; a
quenching furnace in which a temperature can be configured as 880 DEG C +-10 DEG C, and a
residence time can be configured as 180 minutes; a
quenching tank in which a temperature of a cooled product is configured as 300 DEG C, wherein a
cooling medium of a water-soluble
quenching liquid is placed in the quenching tank; and a
tempering furnace in which a temperature can be configured as 610 DEG C +-10 DEG C, and a
residence time can be configuredas 180 minutes. The tensile strength of the material is 850Mpa, the yield strength of the material satisfies 700Mpa, and the
hardness HB of the material is 240 to 280. With the material, mechanical requirements of ship-use container lockset material can be satisfied. Also, the material has advantages of low
metal cost, good and appropriate strength, good and appropriate
hardness, good and appropriate flexibility, and good and appropriate
toughness. The heat treatment device has advantages of easy
processing, simple equipment, convenient operation, and low environmental
pollution.