According to the JJF 1550-2015 Calibration Specification for Borehole Clinometer, this paper presents a method of redesign and reform to the supporting platform and clamping mechanism based on the optical dividing head, which can meet the requirement of clinometer calibration. The experiment of a clinometer is carried out by using the equipment. The paper describes the object, the environment, the processing and the result for the experiment, analyses the uncertainty of measurement, and gives the result that the calibration equipment can meet the requirement for clinometer finally. The comparison conclusion with the result by another laboratory is acceptable, which shows the calibration result is reliable. The equipment has the advantages of lower cost and higher accuracy than the test-bed of inclinometer sold in the market.