The invention provides an in-situ processing test device for a material interface, and belongs to the technical field of semiconductor tests. The in-situ processing test device comprises a first vacuum cavity, a second vacuum cavity, a vacuum pipe, a light path coupling device and a transmission device, wherein the first vacuum cavity is connected with the second vacuum cavity through the vacuum pipe; the vacuum pipe comprises a vacuum valve for controlling connection and disconnection between the first vacuum cavity and the second vacuum cavity; the light path coupling device is connected with the second vacuum cavity; and the transmission device is used for transmitting a sample and a probe when the first vacuum cavity is connected with the second vacuum cavity. According to the in-situ processing test device, pollution and oxidization on the surface of a nano material during transmission between processing and testing are avoided; and local electric, optical and photoelectric surface features at room temperature and low temperature, and the features of a surface appearance and a surface structure under atomic resolution are realized.