The invention discloses an injection system. The injection system comprises an injection device and an electric signal detection device. The injection system is characterized in that the electric signal detection device comprises at least one electrode; and the electrode is arranged at the injection end of the injection device. The injection system can accurately position a target injection region so as to accurately inject medicine to a target region of the inner wall of a body cavity. The injection device can be better realized by mounting a bending compensation mechanism for the length of an injection needle, an injection needle locking mechanism, a quantitative automatic injection mechanism and the like.