In the framework of dividend-agency theory, the article studies the relationship among the level of legal protection of investors, product market competition and corporate cash dividend payments and test the impact of market product competition on cash dividend payments at different levels of legal protection for investors. The results reveals that when other treatment conditions remain unchanged, there is a positive correlation between the level of legal protection of investors, product market competition and the extent of company cash dividend payments. When the level of legal protection is low the impact of competition in product markets on the company's cash dividend payments is more significant. We further conclude that the intense competition in product markets can make up for the lack of legal protection for investors and protect the interests of investors when the level of legal protection is low.