Abstract: Multinucleon transfer reaction ¹³⁶Xe+²⁰⁸Pb at E_\rmc.m.=617 MeV is simulated by improved quantum molecular dynamics (ImQMD) model with and without considering the effect of Q-value. The calculation results of ImQMD including the effect of Q-value (ImQMD+Q) generally better reproduce the experimental mass distribution and distribution of total kinetic energy lost (TKEL). Q-value effect is found to drive the transfer of less than ten nucleons and suppress more nucleons transfer. It also decreases the average lifetime of composite systems in the events at lower impact parameters. In the production of more neutron-rich isotopes with neutron number N=126, Q-value effect enhances the cross sections for these isotopes in the comparison between the results of ImQMD and ImQMD+Q.