The effect of high hydrostatic pressure (up to 18 kbar) on the galvanomagnetic properties of n- and p-Pb_1-xSn_xSe (x<or=0.06) alloys irradiated with electrons (T approximately=300 K, E=6 MeV, Phi <or=7*10¹⁷ cm^-2) has been investigated. It is shown that irradiation creates a band of localized states E_t1 the energy position of which relative to the valance band top L₆⁺ depends on alloy composition and on pressure. A model of the energy spectrum of electron-irradiated Pb_1-xSn_xSe has been proposed assuming that electron irradiation generates two different types of defects and leads to the appearance of two bands of localized defect states situated within the conduction band and near the valence band top of Pb_1-xSn_xSe alloys.