A self healing agent was prepared using gypsum as a bacterial carrier, calcium lactate and urea as substrate. Microbially induced carbonate precipitation(MICP) technology was used to achieve self healing of coral sand mortar cracks. The feasibility of using gypsum as a bacterial carrier to repair cracks in coral sand mortar was verified. The effects of self healing agent content and curing method on self healing performance were investigated. The mineral composition and morphology of the products in the crack were analyzed. The results show that cracks of the samples added with gypsum carrier have good self healing performance. The calcium carbonate produced in the cracks is mainly calcite and vaterite. When the content of carrier and substrate is 3%, cracks of the sample have good self healing performance, and the impact on the strength of coral sand mortar is relatively small.