In this paper, silk fabrics were dyed with natural dyestuff copits. The effects of dyeing PH value, temperature, time, and dye solution concentration on the K/S values were studied. The ultrasonic dyeing was compared with conventional dyeing. The results showed that the optimal conventional dyeing process were dyeing PH value neutral, temperature 100°C, time 40min, the relative dyeing solution concentration 3%, and the optimal ultrasonic dyeing process were dyeing PH value neutral, dyeing temperature 40°C, time 40min, the relative dyeing solution concentration 3%. Ultrasonic dyeing process greatly improved the dye uptake and made obvious effects on energy saving.