The special structure and mineral composition of loess lead to its easy disintegration in water, and lead to a series of geotechnical engineering problems such as slope instability and collapsible settlement. Microbially induced calcite precipitation (MICP) technology is a new microbial mineralization technology. In this paper, the effects of curing age and cementing fluid concentration on the disintegration time and disintegration rate of MICP modified loess were investigated by means of self-made disintegration instrument. Based on the single value effective stress formula of unsaturated soil, the mechanical model of unsaturated soil disintegration was established from the view of pore water pressure and pore air pressure. The disintegration rate-time formula was used to fit the disintegration curves of loess samples. The results show that the disintegration rate of MICP modified samples are lower than unmodified samples. With the increase of curing age, the disintegration time of 0.6 mol/L cementing liquid modified loess increases from 12 min to 28 min. After curing for 14 d, the disintegration rate of MICP modified loess reaches the lowest value of 0.02%, and the adjusted goodness of fit of the disintegration rate-time formula to disintegration rate curve is above 0.90.