Transductive zero-shot learning (TZSL) has been proposed to address the domain shift problem by leveraging additional unlabeled unseen data to enhance the generalization ability from seen classes to unseen target classes. Existing TZSL methods primarily focus on mitigating the distribution bias problem by incorporating these unlabeled samples into the generative models. Although these methods have achieved great success, they do not fully exploit the potential of these unlabeled target data. In this paper, we propose a bidirectional weakly guided conditional generative modeling approach, which utilizes the attribute regressor and the visual generator to synthesize paired training data of unseen classes for each other, thus converting unlabeled target data into matched feature-attribute pairs. Additionally, on top of the generative modeling, we also propose to progressively estimate the associations between visual features and attributes among the unlabeled target data through a semi-supervised pseudo-labeling approach, so as to further facilitate the generative model and enhance the learning of target distributions. Extensive experimental results on four benchmark datasets demonstrate the effectiveness of the proposed method, achieving superior performances to state-of-the-art methods. Our source code is released in: https://github.com/LevisWei/semi-zero-master.