Public hospitals in China predominantly rely on incremental budgeting for operating revenue, a method that extrapolates from historical data and suffers from limited strategic orientation, structural inertia, and disconnection from operational realities. Drawing on cybernetic management theory, this paper reframes revenue budget preparation as a multi-objective planning process under resource constraints, and proposes a three-stage improvement pathway: operational profiling - scenario simulation - budget and key performance indicator decomposition. The approach is demonstrated using 2025 diagnosis related group-based data from the plastic surgery and burn department of a public hospital, yielding a replicable methodology for refining budget management in public hospital settings.