Abstract: The value of pulsed laser energy-equivalent heavy-ion LET has been theoretically analyzed with respect to the impact of a passivation layer on device surface on the equivalent calculation between pulsed laser energy and heavy ion in laser simulation of Single-Event Effects.Modulated by passivation layer of SiO₂ on device surface,laser light intensity transmitted into the silicon substrate is only 21.6%～16.1% that incident on device surface.More accurate value of the pulsed laser energy-equivalent heavy ion LET can be acquired by the pulsed laser intensity transmissivity function if passivation layer thickness is foregone and non-linear effects is neglected.The result calculated in theory accords well with heavy ion LET value reported in some correlative references.