The invention discloses a test device of a model for manufacturing rock masses containing interlayers and a test method thereof. The test device of the model for manufacturing the rock masses containing interlayers comprises a semicircular angle device, an upper baffle, a lower baffle, a left side plate, a right side plate, a circular turntable, a core-drilling machine drill bit, a flat plate, a flat plate angle control rod, a fixed screw rod, a base plate, an interlayer model test piece, a U-shaped plate and a guide slot. The test method comprises the following test steps: arranging the rock masses according to an outline central line and fixing the rock masses; manufacturing interlayer materials and casting the model, fastening the test piece, drilling the core, replacing the core-drilling machine drill bit, changing the position of the test piece to drill repeatedly and cutting to obtain the test pieces with different height-diameter ratios or obtain the test pieces with different interlayer inclination angles; then carrying out mechanical test. The test device is simple in structure and suitable for manufacturing the test pieces with different interlayer thicknesses, inclination angles and height-diameter ratios; according to a core-drilling and cutting machining device, by making full use of the existing device, the influence on the mechanical properties of the test pieces caused by different conditions can be analyzed, coring of irregular rock samples taken in the site can be carried out directly, so that the test efficiency is improved and the test time is shortened.