The invention relates to a lauric acid modified (SOD) preparation method, mainly aiming at solving problems that in the prior art, toxic substances are doped and SOD, becomes inactive (short inactivation time and short half-life period) after being stored for long time at room temperature, while preservation of SOD activity is key of actual application and no precedent of applying the SOD to occupational dermatosis at present exists. The lauric acid modified SOD preparation method mainly comprises the following steps: (1) reacting lauric acid and sulfoxide chloride at 50-140 DEG C, refluxing stably, decompressing and distilling to collect fracture at 124-127 DEG C, thus obtaining an activated lauric acid modifier; (2) dissolving ox blood SOD in a buffer solution, adding the activated lauric acid modifier, stirring and reacting, quenching and terminating reaction to obtain finished lauric acid modified SOD. The technical scheme of the product prepared by using the method in the invention better solves the problems, and is applicable to preparation of lauric acid modified SOD.