Abstract: The development tendency and application foreground of nonlinear analysis technology at home and abroad in multiphase flow are introduced in detail. The application of fractal theory and wavelet theory in multiphase flow is emphatically demonstrated. The work aims at full and accurate expounding internal rules of multiphase flow, especially oil-gas-water three-phase flow which widely exists in petroleum engineering. The authors expect that the work can conduce to experimental research and engineering application in multiphase flow.