We report the magnetic dynamics of as-deposited Mn2Au/CoFeB heterostructures via time-resolved magneto-optical Kerr effect (TR-MOKE) spectroscopy. Increasing the pump fluence from 5 to 25 mJ/cm2 results in an effective demagnetization field 4πM_eff decreasing from 9.178 to 7.483 kOe, accompanied by magnetic damping α_0 decreasing from 0.0225 to 0.0110. The concomitant modulation of 4πM_eff and α_0 is elucidated through the mechanism that the pump excitation with elevated fluence suppresses the antiferromagnetic (AFM) order of Mn2Au and antiferromagnetic-ferromagnetic (AFM-FM) exchange coupling by thermal effect, thereby reducing both 4πM_eff and α_0. These findings provide critical insights into femtosecond laser-modulated magnetic dynamics of AFM/FM bilayers and pave the way for AFM/FM applications in spintronics.