Penicillin skin test and cephalosporin skin test operation process is basically similar, but the mechanism of action and the significance of the results are not exactly the same, so they can not replace each other, but because of penicillin and cephalosporin drugs cross allergy phenomenon, if one is allergic to one kind of allergy, at the same time, it is not recommended to use the other kind. Penicillin skin test and cephalosporin skin test are both used to observe whether allergic reaction occurs in the body by applying a small amount of localized medication under the skin, which can effectively indicate whether the body is suitable for this kind of medication to avoid serious adverse drug phenomena. In the skin test inoculation site local will appear obvious subcutaneous elevation, which contains a small amount of drug liquid, can be observed through the binding with the surrounding cells to observe the allergic reaction. However, penicillin allergy is the observation of allergic reaction by injecting penicillin liquid. Cephalosporin skin test, on the other hand, refers to the local injection of cephalosporin liquid for allergic reaction observation. The mechanism of action and drug composition of the two drugs are not exactly the same, so the significance of a positive result is not exactly the same. Therefore, the results of cephalosporin skin test and penicillin skin test are independent of each other and are not the same, not interchangeable. However, because of cross-sensitization, if one is allergic to the other, the other is not recommended. For example, cephalosporins are not recommended for those allergic to penicillin, and penicillins are not recommended for those allergic to cephalosporins. When performing skin tests, specific injections should be made according to the drug to be used to observe the allergy results, and the skin test results of different drugs should not be substituted for each other.