。
It's too clear to need any proof.
Literal
Clear too-much [and] proof [object-を] not-need.
~すぎる ('too much X') attaches to adjectives and verb stems — here to the な-adjective 明確 (dropping the だ). 要する ('to need/require') is a formal Sino-Japanese verb. The whole phrase is a compressed, nearly aphoristic sentence.