Abstract: The invention provides a suture device, a treatment device with the suture device and a treatment system. The treatment system includes an endoscope and the treatment system. The treatment system is used in cooperation with the endoscope and includes an operating handle and the suture device. The suture device comprises a main shell, a suture needle, a needle feeding assembly and a needle anti-backoff assembly. One end of the suture needle is connected to a suture line, and the other end is a tip. The needle feeding assembly is arranged on the main shell and forms a separable engagement relationship with the suture needle so as to control advancing of the suture needle. The needle anti-backoff assembly is arranged on the main shell and forms a separable engagement relationship with the suture needle so as to prevent the withdrawal of the suture needle.