The invention provides a liquid-vapor two-phase flow tubular shell type heat exchanger. The heat exchanger comprises a shell, wherein the two ends of the shell are separately provided with end sockets, tube plates are arranged at the connecting positions of the end sockets and the shell, and heat exchange pipes are connected with the tube plates at the two ends; a vapor phase in liquid-vapor two-phase flow can be condensed into a liquid phase in the heat exchange process, and the liquid-vapor two-phase flow flows in a tube pass; and flow stabilizing devices used for reducing vibration and noise are arranged in the heat exchange pipes, a plurality of flow stabilizing devices are arranged in the same heat exchange pipe, and the length of the flow stabilizing devices is gradually reduced in the flowing direction of fluid in the heat exchange pipes. According to the heat exchanger provided by the invention, through the length variation of the flow stabilizing devices, when the liquid-vaportwo-phase flow occurs in the pipeline, the vibration of the pipeline is reduced to an utmost degree, and the noise level is reduced; and at the same time, flow resistance is reduced, and the heat exchange uniformity is improved.