Calves are young, tissues, organs and body functions are immature, body temperature regulation ability and disease resistance are poor, and they are prone to diseases, such as pasteurellosis, colibacillosis, mycoplasma pneumonia, cryptosporidiosis, calf neoascariasis, coccidiosis, etc.. The practice of diagnosis and treatment services has proved that penicillin or sulfa drugs should be used in the early treatment of pasteurellosis in calves, and aluminum hydroxide vaccine for bovine hemorrhagic septicemia should be regularly inoculated in the frequently occurring areas. After the calf has colibacillosis, it is necessary to replenish body fluid, inhibit bacteria and diminish inflammation in time. For mycoplasma pneumonia in calves, the principles of early diagnosis, rapid isolation and early treatment should be followed, and sensitive drugs such as enrofloxacin and tylosin should be selected for treatment. Calf cryptosporidiosis should be isolated in time and treated symptomatically. There are many effective drugs to treat calf neoascariasis, including piperazine citrate, levamisole hydrochloride, albendazole, ivermectin, etc.. The best time to treat calf coccidiosis in a large-scale dairy farm should be the third week after the calves are weaned and mixed, it is effective to take toltrazuril.