Mining-Task-Machine is the key technology of the Ocean Mining System. To finalize the design，It is the key step to test the traction and control unit of the Mining-Task-Machine by measuring kinematic parameters with high precision. Mining-Task-Machine moves in a large area in water, a binocular measurement method with wide-angle lens is used to make real-time track and measurement of the trajectory of Mining-Task-Machine. Firstly, the lens distortion is calibrated by using gridding board in lab. Secondly, according to the natural feature, the parameters of the lens distortion is modified based on the result in lab and all the camera parameters are calibrated. Finally, the binocular system tracks a cooperative feature on Mining-Task-Machine and measures the motion trajectory including position and velocity, etc. of it on real time. The residual between the result of the system and the total station is about 5 mm. The system has passed the examination and evaluation, and has been put into use.