The metal-bonded diamond grinding wheels wear out obviously in grinding process of hard and brittle materials such as SiC ceramics, and the shape accuracy will be destroyed, which will affect the grinding surface accuracy and surface quality. In this paper, a swing arm type electric spark dressing device is designed based on the characteristics of metal-bonded grinding wheel, which can realize high dressing precision. Then the electric sparking experiment was carried out using the dressing device. The experimental results show that higher dressing efficiency and low arc precision can be obtained with large electrical parameters, while higher arc precision and lower efficiency could be obtained with small electrical parameters. Therefore, the experiment can guide the selection of different parameter combinations in different dressing stages to improve the dressing efficiency and precision