<p>Fully understanding the response law of drilling parameters during drilling is an important basis for realizing the identification of rock mass properties while drilling. In this study, based on the rock breaking force characteristics of polycrystalline diamond compact (PDC) bit, the governing equations of drilling response parameters and operating parameters were derived. The response law of torque and penetration rate to thrust and rotating speed in the drilling process was studied. The dominant factors affecting the change of drilling response parameters were revealed. Finally, the drilling response law was further explored by digital drilling experiments, and the reasonableness of the governing equations was validated. The results indicate that the torque is only affected by thrust when drilling the same rock. The penetration rate is affected by both thrust and rotating speed. When the drilling operation parameters are the same, the dominant factors affecting the drilling response parameters include the bit size and rock properties. In terms of rock properties, the sliding friction coefficient of rocks is crucial for determining the torque, and the required energy for breaking unit rock is crucial for determining the penetration rate. In the study of rock mass properties identification based on drilling parameters, more attention should be paid to whether there is a strong relationship between the target properties of rocks and the sliding friction coefficient as well as the required energy for breaking unit rock. This study can provide a theoretical basis and reference value for the establishment of a universal rock mass properties prediction method while drilling.</p>