Abstract: In this paper, a novel in-contact 3D measuring device, called MultiCal, is proposed as a convenient, low-cost (less than $5,000), and robust facility for onsite kinematic calibration and online measurement of robot manipulator accuracy. The device has µm-level accuracy and can be easily embedded in robot cells. During the calibration procedure, the robot manipulator first moves automatically to multiple end-effector orientations with its Tool Center Point (TCP) constrained on a fixed point by a 3D displacement measuring device (single point constraint), and the corresponding joint angles are recorded. Then, the measuring device is precisely mounted at different positions using a well-designed fixture, and the above measurement process is repeated to implement a multi-point constraint. The relative mounting positions are accurately measured and used as prior information to improve calibration accuracy and robustness. The results of the theoretical analysis indicate that MultiCal reduces calibration accuracy by 10% to 20% in contrast to traditional non-contact 3D or 6D measuring devices (such as laser trackers) when subject to the same level of artificial measurement noise. The result of a calibration experiment conducted on a Staubli TX90 robot shows that MultiCal has only 7% to 14% lower calibration accuracy compared to a measuring arm with a laser scanner, and 21% to 30% lower time efficiency compared to a 6D binocular vision measuring system, yielding maximum and mean absolute position errors of 0_.831mm and 0_.339mm, respectively.