The invention relates to a sheet billet continuous casting and rolling production line and a production process thereof, and belongs to the technical field of sheet billet continuous casting and rolling. According to the technical scheme, the sheet billet continuous casting and rolling production line comprises a continuous casting machine (1), a 1#pendulum shear (3-1), a 1#tunnel type heating furnace (9-1), a 1#descaler (7-1), a roughing mill group (10), a 2#pendulum shear (3-2), a billet picking device (4), a 2#tunnel type heating furnace (9-2), a 2#descaler (7-2), a finishing mill group (11), a laminar cooling (18), a flying shear (19) and a reeling-up machine set (20) which are arranged in sequence according to a rolling sequence. When the continuous casting speed of the continuous casting machine (1) is less than 5m/min, single block rolling or semi-endless rolling is adopted; and when the continuous casting speed of the continuous casting machine (1) is greater than or equal to 5m/min, endless rolling is adopted. The sheet billet continuous casting and rolling production line and the production process thereof have the beneficial effects that the temperature uniformity and the surface quality of a casting blank can be ensured, and different rolling modes can be adopted according to the continuous casting speed of the continuous casting machine.