The invention discloses a device for drilling a core at a fixed angle in a rock mechanics laboratory. The device for drilling the core at the fixed angle in the rock mechanics laboratorycomprises a base part, a bracket part, and a lateral limiting part; cambered surface grooves penetrating through a pair of lateral surfaces are formed in the top surface of a base of the base part, limiting clamping grooves in the axial directions of the cambered surfaces are sequentially formed in the cambered surfaces of the cambered surface grooves, and the bracket assembly comprises an angle bracket formedby two brackets, and the two brackets of the angle bracket are fixedly connected at a certain angle; the lateral limiting partcomprises clamping armsarranged on two penetrating sides of the base correspondingly. According to thedevice for drilling the core at the fixed angle in the rock mechanics laboratory, the limiting clamping grooves on the base are sued for cooperating with the angle bracketwith a certain angle, a bedding angle core commonly used ina rock mechanics test can be simply and conveniently drilled; and the clamping arm structure capable of adjusting the clamping positionaccording to the shape and size of the core within a certain range through the lateral limitingpartis arranged, and the defect that that only a regular shaped rock sample can be clamped by a vise of a conventional drilling machine is avoided by the clamping arm structure.