The paper is devoted to development of laser differential synchronous cloudy triangulation methods for thickness measurements in the hot metallurgical industry. The method of laser differential cloudy triangulation with video stream synchronization is proposed. This method makes it possible to use widely available and very reliable photodetectors without hardware synchronization. The proposed method is implemented in a prototype of a laser radiation-safe hot-rolled meter and tested in the hot-rolled section of Novosibirsk Metallurgical Plant. During tests, the measuring complex provided a measurement error 0.01% and confirmed its performance in the conditions of hot metallurgy. Application of the proposed method of video stream synchronization of photodetectors allows reducing the cost and increasing the reliability of the modern measuring systems based on laser differential cloudy triangulation.