Painless injection for normal labor refers to painless labor injection, which generally lasts for 6 to 8 hours, but the details vary from person to person. The painless injection is a lumbar spinal puncture in the process of labor, using intralesional anesthesia to relieve labor pain, generally after the injection of the drug lasts 6 to 8 hours, but the specific circumstances vary from person to person, and the maternal drug absorption has a great deal to do with some mothers may be a shorter period of time, in about 4 hours. Painless injection in labor is not completely painless, but only to a certain extent to alleviate the pain of the mother, in labor to relax, avoid excessive emotional tension, adjust their mood, pay more attention to rest. Some women who are allergic to anesthesia drugs are not recommended to have painless injections, and need to choose the mode of delivery under the professional guidance of the doctor.