Green credit is a market-oriented financial instrument. Green subsidies are government-led fiscal instruments. Both are important policy instruments for directing resources toward green sectors. However, existing studies have generally examined the two instruments separately, with few comparing their target recipients and low-carbon resource allocation characteristics within a unified framework. This study develops a theoretical model incorporating firms, banks, and the government and compares the allocation of capital and output to low-carbon firms relative to high-carbon firms under alternative policy scenarios. Building on this framework, this study conducts an empirical analysis using data on China’s A-share listed firms. The results show that corporate carbon emission intensity is significantly negatively associated with the probability of obtaining both green credit and green subsidies, indicating that both types of policy resources are generally allocated preferentially to low-carbon firms. Compared with green subsidies, green credit exhibits stronger screening of low-carbon firms. This study reveals differences between green credit and green subsidies in low-carbon resource allocation and provides guidance for improving both policy instruments.