Based on the traditional saddle instrument, a portable roll-profile measuring device based on a contact sensor is designed and optimized. The positioning module is added via the machine vision method, which enables the automatic reading of measurement points. The measurement accuracy of the device is 1 μm. Possible errors caused by the process of installing the roll-profile meter are analyzed, and the installation requirements of the measuring device are provided. On this basis, the compensation method for roll measurement with the roll profile is also improved. The accuracy of the measuring device is verified by measuring the roll on the spot, and the measurement error of the flat roll is 0.02 mm. When measuring the roll crown, the measurement accuracy is improved by 69% after the compensation algorithm is applied. The measurement results meet industrial measurement requirements, which is highly significant to the intelligent operation and maintenance of the roll.