Within the framework of an isospin-dependent quantum molecular dynamics (IQMD) model,the emission features of light particles in 112Sn+112Sn and 124Sn+124Sn are investigated at different beam energy,different impact parameter,different EOS and different nucleon-nucleon cross section.Calculations show that the ratios of light particles are consistent with the systematics of entrance channel isospin and the midrapidity region can emit more neutron-rich particles than projectiles-like rapidity.In addition,it is found that the light particle ratio is sensitive to the nuclear EOS,but not to the nucleon-nucleon cross section,which makes it possible to extract the isospin-dependent EOS.