该剧讲述了心怀正义、一心为民的刺客郑轲为了刺杀民间传闻中荒淫无度的皇帝，不小心与公主齐婉儿互换身体，在完成任务的过程中，俩人互生好感，期间发现一切都是由奸臣设计陷害皇帝，于是毅然帮助皇上铲除奸佞，并与公主喜结连理的故事。

該劇講述了江湖第一刺客鄭軻為報殺父之仇，入宮準備刺殺當朝聖上，卻未曾想一場巨大的陰謀即將揭開。蟄伏入宮的鄭軻偶然與集萬千寵愛於一身的公主齊婉兒互換了身體，於是兩人開始共同尋找換回去的方法，隨著瞭解的加深，兩人從彼此猜忌到相互保護、互相體諒，逐漸堅定了對彼此的感情，也攜手推翻了妄圖謀反的丞相的陰謀......

Zheng Ke, the number one assassin in the world, who went to the palace to prepare to assassinate his father in order to avenge his death. However, he never imagined that a huge conspiracy was about to be revealed. Zheng Ke, who was dormant in the palace, accidentally exchanged bodies with Qi Waner, the princess who was loved by thousands of people. So, the two began to look for a way to switch back together.

As their understanding deepened, the two went from being suspicious of each other to protecting and understanding each other, gradually strengthened their feelings for each other, and worked together to overthrow the conspiracy of the prime minister who attempted rebellion...