Abstract: As a traditional survey and design enterprise, China Coal Tianjin Design Engineering Co., Ltd. closely follows the great changes in the coal industry and actively responds to the "3060" major strategy. Combined with the development of diagnosis and optimization of production mine system, it summarizes the main principles that should be grasped, puts forward the "four times and five steps" working method, the "three comparisons" working principle and three characteristics that should be grasped in optimization, It provides a new way for the company's business transformation and development. With the goal of safety, efficiency, intelligence, green and low carbon, we will gradually explore a path to realize the advanced and advantageous production capacity of coal, and achieve win-win results for both sides on the basis of providing value-added services for coal mines.

Key words: "Four-and-Five-Step", Working Method