The invention discloses a multi-energy complementary system operation boundary analysis method considering load uncertainty. A traditional analysis method based on an interval form cannot consider thecorrelation among various uncertain factors, and the conservative property of the calculated operation range is too large. The multi-energy complementary system operation boundary analysis method adopts an uncertain set analysis method, firstly, establishes a steady-state energy flow calculation model of the multi-energy complementary system, then performs modeling load power fluctuation by adopting a Zino polyhedron, and calculates all change ranges of state variables of the system by linearizing energy flow, thereby analyzing an operation boundary of the multi-energy complementary system under the condition of uncertain load fluctuation. According to the multi-energy complementary system operation boundary analysis method, the calculation speed is high, and all possible values of the state variables under the uncertain condition can be obtained through one-time energy flow calculation and linear transformation, and the multi-energy complementary system operation boundary analysis method can adapt to a high-dimensional variable space, can effectively process the coupling relation between various energy systems, and can improve the efficiency and precision of multi-energy complementary system operation boundary analysis.