Temporal characterization is important to diagnose and measure a petawatt (PW) class laser. We obtained the V curve of the pulse width versus the grating position using pulse width measurement with a mirror image configuration. The temporal range for pulse width was 18 ps with a resolution of 0.05 ps. We measured the pulse contrast between the -60 ps and -6 ps PW class laser within a single shot in the Shen Guang II facility. We measured the pulse contrast between the -91 ps and -60 ps PW class laser after expanding the temporal range. The temporal range was 70 ps, with a dynamic range of eight orders of magnitude.