Abstract: It will be very difficult to continue to improve when the positioning accuracy of the computerized rock drill reaches 10 cm for the reason of machining.In order to analyze the influence of joint clearance in specific location on the process of carriage and drilling positioning quantitatively, the model of computerized rock drill is established.The measurement experiment is designed to detect the operation of the feed beam, the functional relationship is analyzed between the collapse values of tool and pose parameters of drilling.The original carriage positioning method is revised to compensate for the positioning accuracy of drilling, and the effect of error compensation is verified by field drilling positioning test.The results show that the stroke of linear cylinder has the obvious effect on the collapse values of the tool, and the pose angles of the blast-hole have an irregular effect on B.By analyzing the measured data, it is known that there is an approximately linear relationship between the collapse values of tool and the stroke of linear cylinder, and the change in the pose angles of the blast-hole has little effect on the relationship.Thus the original carriage positioning method is corrected based on the function.By comparing the results of the two methods, one is the calculated method, and the other is the real results measured by the total station, it is found that the vertical position error is within 5% and the angle error is within 0.2°, which is proved the reliability of the correction method.Then the compensation for drilling positioning errors can reduce its mean values by 11%-16%.These operations have the key significance for the correction of the kinematic model next step and the ultimate achievement of the control target of precision.It is worth noting that the single-arm positioning method has the problem of transmitting and amplifying the error to the non-positioning side, which results in the mean results of the positioning errors in the non-positioning side to be 1.78 times that of the positioning side.The method of compensating for joint clearance is hard to reduce the gap between the positioning errors of the two sides, there are other means to be used to solve this problem.