To address the problems in the existing methods for radar signal feature recognition: the poor performance in low Signal-to-Noise Ratio (SNR) environments and the difficulty in handling multiple tasks of classification and parameter estimation simultaneously, a hybrid multi-task learning method fusing Convolutional Neural Network (CNN) and Transformer was proposed. In the method, multi-scale local feature extraction was integrated with global dependency modelling. To further achieve balanced joint optimization, a dynamic task weighting strategy fusing Bayesian uncertainty estimation and task-difficulty awareness was introduced to adjust the loss weights adaptively. Besides, an attention visualization module was developed to enhance model interpretability. Experimental results on the RadChar-Baseline dataset show that compared with baseline models such as IQST (IQ Signal Transformer), CNN1D (One-dimensional Convolutional Neural Network), CNN2D (Two-Dimensional Convolutional Neural Network), ResNet1D (One-Dimensional Residual Network), and Long Short-Term Memory (LSTM) network, the proposed method achieves a composite score of 0.931; within the SNR range of -20 dB to 20 dB, it has an average composite score of 0.937 with a standard deviation of only 0.108. It can be seen that the proposed method significantly outperforms the comparative methods in both classification and regression tasks, especially under challenging low SNR conditions.