A petawatt (PW) beam line, which will deliver 1 kJ pulses with pulse duration near 1 ps, is being set up. Similar to the other high peak-power laser systems, the design of PW beam line also builds on chirped pulse amplification (CPA) techniques. Several new components except for the existing amplifier chain of the ninth beam in Shen-Guang-II (SG-II) facility are introduced, such as an optical parametric chirped-pulse amplification (OPCPA) in front-end subsystem, the deformable mirrors and the chirped pulse compressor with tiled gratings in rear-end subsystem.