泥古不化

nìgǔbùhuà
conservative and unable to adapt (idiom)

CEDICT

泥古，拘泥于古代的成规或古人的说法。泥古不化指拘泥于古代的制度或说法，不知根据具体情况，加以变通。

重編國語辭典

Entry Composition

1 泥古 nìgǔ
  1. stick-in-the-mud
  2. to stick to old ways
  3. stubbornly conservative
2 不化 bùhuà
  1. (literary) to not change; to be unchanged
  2. (literary) to not decay; to not spoil
  3. to not change; to be unchanged
  4. to not decay; to not spoil