A detection method of Edge Coherent Mode based on improved SSD

•Single-shot multibox detector (SSD) is studied to apply to detect ECM.•The positive-negative sample ratios of SSD are adjusted to improve detection accuracy.•The flooding loss is imported to suppress overfitting of SSD and improve model robustness and detection accuracy.•The proposed improved detection method applies for subsequent intelligent data analysis and provides reference for physical events detection in fusion experiments.