The present invention relates to a novel process for refining the liquefied petroleum gas (LPG) in a commercial scale. The process comprises: sequentially performing fine desulfurization and mercaptan conversion of the LPG after alcohol amine treatment through desulfurizer and catalyst set in fixed bed reactor in the absence of alkali, wherein, during the fine desulfurization, the resultants of reaction between hydrogen sulfide in the LPG and Fe--Ca oxides or their hydrates adhered on the desulfurizer, and during the mercaptan conversion, the mercaptan in the LPG reacts with the residual trace amount of air in the LPG under the action of the catalyst to produce the disulfides; letting the formed disulfides along with the LPG flow out of the fixed bed reactor; rectifying the LPG after the mercaptan conversion to obtain the refined LPG products, with further rectification to obtain the valuable disulfide products. The present process has advantages of high efficiency, no alkali discharge, being a simplified process over the prior method using alkali treatment and making no environmental pollution.