Method for producing thin-specification SAPH440 steel based on ESP thin slab continuous casting and rolling process

The invention provides a method for producing thin-specification SAPH440 steel based on an ESP thin slab continuous casting and rolling process. The method includes the steps that raw materials are selected, wherein the raw materials include, by mass percent, 0.04%-0.10% of C, 0.15%-0.45% of Si, 1.00%-1.50% of Mn, 0.008%-0.045% of Alt, smaller than or equal to 0.0030% of S, smaller than or equal to 0.015% of P and the balance iron; the raw materials are subjected to converter smelting and LF furnace smelting; molten steel formed from an LF furnace passes through an ESP production line to generate hot-rolled strip steel different in thickness, wherein in the ESP production line, the temperature of a rough rolling inlet ranges from 950 DEG C to 1050 DEG C, the temperature of a finish rolling outlet ranges from 800 DEG C to 870 DEG C; and the hot-rolled strip steel is cooled to the temperature ranging from 530 DEG C to 680 DEG C and then enters a coiling machine to be coiled, then scale breading acid pickling is