Current stone countertop production process is worn the following problems: long handling distance, long handling time, loose process cohesion, low balance rate, etc. In order to solve these problems, an automatic production line is proposed. In the production line, roller conveyer is used as the logistic system. The selected CNC equipment adopts an open structure and an oblique base. The ... [Show full abstract] equipments are arranged into a U-shape line combined with unit layout. In order to increase the flexibility of the production line, the whole production line is divided into two level modules. According to the design rules of the automatic production line, two examples are planned and are simulated based on EM-Plant. The simulation results show that, compared with the current production process, the automatic production line has the following advantages: the transit distance is shortened more than half, the transit time is reduced to about 1/7, and the balance rate increases by 20%, the output is nearly doubled, while the number of workers does not increase.