Abstract: Using processed tomato KT-7 as material, under hydroponic conditions.The effects of exogenous salicylic acid (SA，0.15mmol/L) and hydrogen sulfide (H2S) donor sodium hydride (NaHS，50mmol/L) on osmotic regulation，reactive oxygen metabolism and rapid chlorophyll fluorescence of tomato seedlings under 150mmol/L NaCl stress were investigated，The synergistic effect of H2S and SA signaling molecules was investigated to provide theoretical basis for the physiological mechanism of alleviating salt stress in processed tomato seedlings. The results showed that exogenous SA，H2S and their combination treatments could effectively alleviate the NaCl stress injury of processed tomato seedlings. The chlorophyll content，relative water content of leaves and proline content of processed tomato seedlings were improved to different degrees compared with the salt stress treatment；However，the content of malondialdehyde (MDA)，electrolyte permeability and hydrogen peroxide (H2O2) content of each exogenous SA and H2S treatment were decreased to different degrees compared with the salt stress treatment；Among them，the MDA content, electrolyte permeability and H2O2 production rate of the processed tomato seedlings under the combined treatment of root application of exogenous 0.15mmol/L SA and spraying of 50mmol/L H2S all reached the minimum，while the proline content of the mixed treatment seedlings reached the maximum.