During the fast measurement process of measuring the bearing cylindrical roller diameter, the sensor contact deforms due to the applied force produced when the sensor contact approaches the roller, which may reduce the measurement accuracy. Therefore, this workproposesa contact dynamics research methodology considering the microscopic deformation. Based on Hertz contact theory, nonlinear damping theory and Coulomb friction theory, a kinematic differential equation between the contact and the roller isestablished based on the sensor contact deformation during dynamic measurement. Different measurement speed, position angle and deformation amount areobtained by analyzing the relationship between the normal force and the deformation at the contact point. In addition, the test results from the virtual simulation and the physical prototype experiment show that the roller diameter measurement error is no more than 1 μm. By quantifying the relationship between measurement speed and measurement accuracy, this workcontributes to the bearing cylindrical roller diameter measurement studies, and provides a theoretical basis for efficient and accurate contact measurement of the diameter of cylindrical parts in practical engineering applications.