The invention discloses a test device for observing a hole machining outlet, belongs to the technical field of hole machining, and relates to a test device and a test method for observing hole machining outlet, and the device and the method are especially suitable for studying a machining process of carbon fiber reinforced composite holes. The device comprises a microcomputer system, a horizontal drilling test table, a high-speed microexamination device, an on-line outlet temperature measuring device and a dust removal device. The method comprises the following steps: firstly adjusting a drill clamped on the front end of an angle head to a to-be-machined position, determining the expected center of a drilling hole outlet according to the intersection point of the axis of the drill and a to-be-machined test piece outlet side, and marking, and adjusting a high-speed camera and a thermal infrared imager to determine a view field, and focusing correctly. According to the device and the method, the crosswise drilling machining is realized by the angle head, the outlet temperature can be measured in an on-line manner, a hole outlet cutting process can be observed in a stable, clear and multi-angle manner, and real-time conditions of cut shapes and temperature values of materials in a cutting area in the cutting process can be obtained.