This thesis takes The Sutra of the Merit and Virtue of the Past Vows of Medicine Master Vaidurya Light Tathagata as the text of study. The main point of the first half of this classic is the content of the Twelve Great Vows of Medicine Master Tathagata. Based on the characteristics of each one of the twelve Great Vows, analyze the similar connotation between Four Noble Truths and the characteristics of each vow, in order to understand the facts of suffering and the causes of suffering in worldly rules, as well as practicing the cause of exterminating suffering and reaching the state of extermination in transcending worldly rules. And the other half point of this classic, for Medicine Master Tathagata is based on compassion, for the benefit of all beings, and when the life of all beings encounters death and disaster, the holder of Medicine Master Tathagata gains the benefit of both life and death. The benefits of life include the elimination of greed, anger, and ignorance in order to purify the mind and gain the benefit of not falling three lower realms; and the benefits of life, such as the elimination of disasters and the relief of evil, due to the concentration to induce the mind of Medicine Master Tathagata. The benefits of death After receiving eight precepts, the understanding is like words and deeds, and you will be benefited from living in the pure land, heaven and the upper human class. Therefore, in a nutshell, not only can we learn human happiness according to the the Dharma, but more importantly, if we can deeply understand the connotation of Medicine Master Tathagata who issued the Vows, we should be able to gain even more happiness.