The invention discloses a device for testing a basic friction angle of a rock joint under real-time high temperature conditions. The device comprises a heating box, a frame, a reversing gear set and amotor. The heating box is formed from a bottom plate, a top plate and side plates. One side of the bottom plate is arranged above the frame and the other side of the bottom plate is hinged to the frame. An axle is arranged in the middle of the bottom of the bottom plate. An input end of the reversing gear set is connected to the motor. An output end of the reversing gear set is connected to the axle. The device can test the basic friction angle of a rock joint in a real-time high temperature environment. The heating rate and temperature in the high temperature environment can be set accordingto demands. The device is suitable for study in various temperature environments. The tilt rate and the tilt angle can be set according to demands. The device has a wide application range and produces research results with high feasibility.