Injection device

An injection device configured to be loaded with a syringe including an injection container and a needle, or loaded with an injection container and a needle, wherein, the injection device comprises:

• an injection site gripper, comprising:
• at least one of a negative pressure suction mechanism and a mechanical compression mechanism;
• an accommodating portion configured to be disc-shaped, have an arched cross-section, raise and grip epidermis and subcutaneous tissue at an injection site by the at least one of the negative pressure suction mechanism and the mechanical compression mechanism, and provided with an opening to expose at least a portion of the raised and gripped epidermis and subcutaneous tissue at the injection site;
• a height restriction portion configured to have a transversal extending portion, the opening of the accommodating portion being located inside of the transversal extending portion, so that a height of the exposed at least portion of the epidermis and subcutaneous tissue at the injection site is lower than that of the transversal extending portion, wherein the needle is only able to actively penetrate into the epidermis and subcutaneous tissue to an appropriate depth, instead of passively penetrating therein when the epidermis and subcutaneous tissue is raised;
• a main machine, which is coupled to the injection site gripper and configured to automatically perform an injection process for the gripped injection site;
• and
• a pressure detector configured to detect a pressure applied by the injection site gripper on the injection site.