Abstract: In the Northwest oilfield, there were some problems for high sulfur-containing associated gas during the desulfurization and purification of dimethylethanolamine (MDEA) solution, such as frequent liquid blocking and flushing tower and the hydrogen sulfide concentration in the purified gas over-standard, etc. The analysis results showed that the high heavy hydrocarbon content in the associated gas system was one of the causes which led to the amine solution foaming and low tray efficiency. A new counter current low backmixing spray state tray structure (SDST) based on the principle of spray state was proposed and designed. The hydraulic test results showed that compared to the F1 float valve tray, the SDST pressure drop could be reduced by 10%, the flux could be increased by 30%, and the operation flexibility was basically unchanged. The industrial application results of SDST trays in associated gas desulfurization process showed that SDST tray has a good foaming suppression performance, which can effectively solve the problem of liquid blocking and flushing tower in associated gas desulfurization process, and at the same time increase the plate efficiency by more than 10%, and also effectively solve the problem of hydrogen sulfide concentration over-standard in the purified gas caused by the low tray efficiency during the associated gas desulfurization process.