In order to analyse the process of change in Northern Song poetry, especially to explore how Ouyang Xiu and Huang Tingjian solved the dilemma of flamboyant poetic style and "previous poems have already been written", we will try to interpret Ouyang Xiu's and Huang Tingjian's poems in depth, analyse their respective theories of poetic method and creative practice, as well as how they influence each other and jointly promote the transformation of Northern Song poetic style. The two poems are analysed to see how they influence each other and jointly promote the change of poetic style in the Northern Song Dynasty. Ouyang Xiu and Huang Tingjian have their own strengths in poetic method. Ouyang Xiu advocated the "correctness and oddness", and he followed Han Yu's example, emphasising the pursuit of innovation and change on the basis of inheriting the traditions of his predecessors; whereas Huang Tingjian took Du Fu as his model and put forward the poetic concept of "correctness and oddness", focusing on making a breakthrough on the basis of the norms. The poetic concepts and practices of the two men not only promoted the transformation of the Northern Song poetic style, but also made Song poetry form a very different style from that of Tang poetry. A comparison of the two is not only helpful in deepening the understanding of the process of change in Northern Song poetry, but also important in recognising the formation mechanism of the unique style of Song poetry.