Each waveguide is connected with the wall surface of the microwave absorption cavity at a predetermined angle that is greater than or equal to 15° and less than 90°, the area of intersection interface between the waveguide and the material pipeline can be adjusted rationally, and due to the use of the tuners, the reflection coefficient during microwave transmission approaches 0, and the voltage standing wave ratio approaches 1, so that the safety of the microwave processing operation process is greatly improved. The microwave absorption cavity is a rectangular cavity, the microwave feed ports are formed in the opposite wall surfaces of the microwave absorption cavity with a certain distance, each waveguide is connected with the microwave absorption cavity through the microwave feed port, and a specific and feasible solution is provided for microwave processing. The inclination directions of the waveguides with respect to the wall surface of the microwave absorption cavity are set to be uniform or partially uniform, so that uniform output or centralized output of microwave energy conveyed into the microwave absorption cavity can be achieved, and specific and feasible solutions are provided for each case. One solution is a microwave processing equipment for continuous flow liquids, which includes a material transmission pipeline inside the microwave absorption cavity. In this solution, flow liquids circulate from the material transmission pipeline. Another solution is a microwave processing equipment for continuous flow liquids, which does not include a material circulation pipeline inside the microwave absorption cavity. In this solution, a sealing material is installed at each microwave feed port, and flow liquids directly circulate from the microwave absorption cavity. The disclosure take full account of the problem of efficiency and uniformity of microwave heating, the utilization rate of energy is improved, it can reach the treatment temperature of the material and effectively solve the fouling problems caused by the traditional heating processes that use high temperature steam as heat source, such as milk UHT sterilization process.