The present invention relates to an FGFR4 inhibitor represented by formula (I), its preparation method and use thereof. The series compounds of the formula (I) developed by the invention has a strong inhibitory effect on the activity of FGFR4 kinase and has a very high selectivity. And it can be widely used in the preparation of a medicament for the treatment of cancer, especially liver cancer, gastric cancer, prostate cancer, skin cancer, ovary cancer, lung cancer, breast cancer or colon cancer, and it is expected to develop into a new generation of FGFR4 inhibitor.本發明涉及一種具有式(I)結構的FGFR4抑制劑、其製備方法和應用。本發明所開發的式(I)系列化合物對FGFR4激酶活性具有很強的抑制作用，並具有非常高的選擇性，可廣泛應用於製備治療癌症特別是肝癌、胃癌、前列腺癌、皮膚癌、卵巢癌、肺癌、乳腺癌或結腸癌的藥物，有望開發成新一代FGFR4抑制劑藥物。
