This injection technique does not need to take the chicks out of the cage, but extends the hand into the cage to carry out the immunization process. The injection device is fixed on the finger, and there is a tiny sensing device on the injection device, which can trigger the injection device after touching the skin of the chicks to complete the injection. The power part uses a micro motor to drive the injection device to realize the injection process. The dose can be adjusted in a small amount. Two kinds of vaccines or antibiotics can be injected at the same time.