Abstract: The application of green deacidification agent (GDAA, developed by Southwest Petroleum University) in the fiber membrane contactor deacidification technology treating straight run diesel fraction from Karamay Petrochemical Company is carried out, as well as the hydrolysis regeneration of spent agent. Results show that the application of GDAA makes up the deficient of single fiber membrane contactor deacidification technology for diesel fuel; in this combination, no acid emulsion and waste discharge, the GDAA can be pyrohydrolysised and recycled. Under the conditions of a mass fraction of organic amine in GDAA of 15%, GDAA/oil volume ratio of 0.3, a reaction temperature (phase separation temperature) of 40 ℃ and a phase separation time of 80 min, GDAA can be recycled effectively for up to 13 times. Spent GDAA can be pyrohydrolysised under the condition of a solvent oil amount of 4 mL/g, a regeneration temperature of 90 ℃ and a regeneration time of 8 h, the regenerated GDAA can be reused for treating diesel oil effectively up to 12 times. As a byproduct, the recovered petroleum acid has a raw acid number of 205.5 mgKOH/g, which meets the requirement of first class 75# acid specifications (SH/T0530-1992).