The invention relates to a production process of chemical products, in particular to a preparation process of sulfurized calcium alkyl with high alkalinity. According to the technical scheme which is provided by the invention, the preparation process of sulfurized calcium alkyl with high alkalinity comprises feeding materials as followed into an autoclave, 77-135 parts of dodecyl phenol, 0-10 parts of low alkalinity sulfonic acid or 9.7-10.7 parts of geoceric acid, 58.5-91.2 parts of medium oil, 35.9-41.5 parts of calcium oxide, 18.8-20.9 parts of sulfur flour and 0-0.8 parts of organic vulcanization accelerator, heating-up and vulcanizing with 90-160 DEG C for 30-45 minutes, generating H2S and water through stripping reaction after vulcanization, conducting calcification, carrying out high calcification after generated water in stripping reaction, dripping ethylene alcohol within 130-160 DEG C, pumping in CO2 after dewatered, dripping ethylene alcohol with 37.8-64 parts and 35.9-41.5parts of CaO, wherein the dripping amount of CO2 is 14.2-172 parts to obtain reaction product, filtering, and steaming out ethylene alcohol in reaction product to obtain sulfurized calcium alkyl product with high alkalinity whose unit is weight part.