Based on listed companies in our country, this article explores the impact of tight money on corporate financing constraints by using cash-cash flow sensitivity model. This study finds that firms in our country usually face financing constraints, tight-money policy aggravates corporate financing constraints through bank lending channel, and meanwhile, no-tight-money policy alleviates corporate financing constraints. In order to relieve the corporate financing constraints, this paper considers that China's financial reform should advance the process of optimizing financial structure closely around the adjustment of banking structure, reduce the effects of corporate financing constraints influenced by bank credit channel, relieve the effect brought by the variation of monetary policy.