In order to solve the problems that the single-baseline transmissometer is a single sampling volume device and effected by noise seriously, a mobile variable baselines visibility detection device is designed and produced. Four modules of emission, receiver, transfer and processor constitute the entire system. The emission sources is 532 nm laser. The trolley is set on the sliding track, receiving the signals in a state of continuous movement. Applying this approach, the multiple baseline visibility detection is realized. Then, the time averaging combing with least squares method is employed to compute the ultimate atmosphere visibility. This equipment only makes the use of single receiver to operate, which can eliminate the error caused by the optical system contamination in theory. By the error theoretical analysis, the detection variance and baseline sampling points models on the proposed system are exhibited, and the anti-noise performance is proved through adding noise simulations on the system. Finally, the entire device is tested in the real atmosphere, it is turned to be reliable by comparing the actual data.