To ensure the long-term self-healing capability of microorganisms is crucial for repairing cracked concrete structures through microbially induced calcium carbonate precipitation (MICP) technology. The long-term microbial self-healing capabilities of cracked mortar mixed with Bacillus Pseudofirmus, exposed to water immersion-ambient exposure conditions, were studied by means of comprehensive utilization of crack geometric measurement, as well as XRD, EDS, and SEM analyses. The experimental results reveal that after a 150 d water immersion period, the crack area repair ratio of the samples with initial width below 200 μm is over 80%. The maximum healed crack with a width of 507.8 μm is observed. Furthermore, denser white precipitates are noted on the surface of those 1 500 d samples, but with a limited efficiency in further reducing crack width. However, the white precipitate observed on the newly saw-cut section of a 1 500 d sample provides evidence that Bacillus Pseudofirmus within the mortar has long-term self-healing capability. The results of XRD, EDS, and SEM analyses confirm that the predominant self-healing product within the cracks is microbially induced calcite.