Abstract: In the context of deepening energy coupling and the high proportion of new energy sources connected to the grid, it is crucial to solve the problem of new energy and load forecast uncertainty in multi-source power systems. The stepped carbon trading mechanism is taken into account when proposing a fuzzy optimal scheduling method for multi-source power systems. The fuzzy affiliation parameter is used to characterize the impact of load uncertainty and new energy on the system. In order to investigate the effects of various uncertainty factors on the system and introduce the stepped carbon trading mechanism, a fuzzy opportunity constraint model accounting for source-load uncertainty is built. CPLEX on the Matlab 2020b platform solves the model. The example results demonstrate how well the suggested model can lower carbon emissions and operating costs.