[Objective] The effects of different precipitation patterns on carbon emission of cyanobacteria crust covered soil were explored in order to provide scientific basis for accurate estimation of carbon emission of ecosystems in arid regions. [Methods] Taking Ulan Buh Desert as a study area, the global climate change was simulated by artificial precipitation enhancement and frequency change. Long-term field monitoring was conducted for soil respiration rate of cyanobacteria crust covered soil. [Results] Precipitation could stimulate the release fluxes of CO₂ immediately. The soil respiration rate reached maximum within 1 hour after rainfall, and fell to a low level in about 12 hours. With the increasing of dry-wet alternation times, the respiration pulse gradually weakened. Compared with the first rainfall, the peak of soil respiration rate was decreased by 40% to 60% after the last rainfall. The 16-hour cumulative release fluxes of CO₂ and the total cumulative release fluxes of CO₂ all increased along with the increase of precipitation size. However, when the precipitation size increased to a certain extent, it had no obvious acceleration effect on soil carbon emission. For a single precipitation, the release fluxes of CO₂ caused by low-frequency heavy precipitation were significantly greater than that of high-frequency light precipitation. With the total precipitation size constant, the release fluxes of CO₂ caused by high-frequency light precipitation was the highest, the low-frequency heavy precipitation was the second, the normal frequency precipitation was the minimum. [Conclusion] Increased precipitation size and changes in frequency caused by global climate change will increase carbon emission of cyanobacteria crust covered soil, suggesting that cyanobacteria should be considered in projections of future carbon budget.