A modulation format recognition(MFI) method based on joint residual network(ResNet) and Bottleneck Transformer (BT) is proposed to meet the transmission requirements in future optical network links. This method combines ResNet and BT to identify signals with six different modulation formats, and applies OptiSystem and TensorFlow to simulate them. The simulation results show that within a wide range of optical signal-to-noise ratio (OSNR), the proposed method achieves an accuracy of 99.72% and can effectively cope with the impact of transmission damage. Compared with other deep learning methods, this method significantly improves its performance.