Acidic gas treating process and system

The invention discloses an acidic gas treating process and system. The acidic gas treating process employs a two-stage gas-liquid two-phase countercurrent absorption reaction and uses a NaOH solution as an absorption liquid to treat acidic gas so as to produce NaHS. According to the process, a primary liquid reaction product and a secondary liquid reaction product are cyclically used, and the primary liquid reaction product is circulated to a secondary intermediate tank and used as a diluent. The acidic gas treating system adopts a rotating bed reactor as a gas-liquid reactor; CO2 in the acidic gas reacts with NaOH to produce nanometer Na2CO3 crystal, so obstruction of a pipeline by the Na2CO3 crystal during fluid conveying is prevented. The acidic gas treating process provided by the invention is simple and can achieve the dual objectives of purification of acidic gas and reclamation of pollutants; and the acidic gas treating system has the advantages of small scale, low energy consumption and low proneness to obstruction.