Surgical sutures for sealing gastric perforations (GP) are associated with severe inflammation and postoperative adhesions. Hydrogel bioadhesives offer a potential alternative for sutureless repair of GP; however, their application in minimally invasive surgery is limited due to their prefabricated patch-form, lacking in situ gelation capability. In this study, we emphasized an all-in-one minimally invasive strategy for sutureless repair of acute GP. an injectable photocurable Janus hydrogel was synthesized, and their ability to seal GP was performed. A rat GP model was used to verify the wound healing and antiadhesion efficiency of hydrogels, and a rabbit GP model was used to verify their laparoscopic feasibility. A fresh human corpse GP model was further employed to verify the user-friendliness of a minimally invasive deliverable (MID) device. A minipig GP model was utilized to evaluate the all-in-one minimally invasive strategy for the treatment of acute GP. Such injectable Janus hydrogel exhibited asymmetric adhesiveness, where the inner-facing side of the hydrogel displays strong sealing and wound healing abilities for GP, while the outward-facing side prevents postoperative adhesion formation. We further developed a minimally invasive deliverable (MID) device integrating hydrogel-delivery parts and photocrosslinking-gelation parts in a laparoscope system. The precise delivery and rapid fluid-tight sealing process of the injectable Janus hydrogel using the MID device for in situ GP repair were demonstrated in a simulated clinical scenario. The effectiveness of GP sutureless repair was successfully validated in porcine models, with further exploration of the underlying mechanism. Our findings reveal that the injectable Janus hydrogel offers an all-in-one strategy for sutureless GP repair and concurrent prevention of postoperative adhesion formation by incorporating the MID device in minimally invasive surgery, presenting the significant potential to reduce patient surgical complications.