A copper-clad aluminum composite wire that can reduce an amount of copper to be used. A structure of the copper-clad aluminum composite wire includes: a wire made of an aluminum material, where a surface of the wire made of an aluminum material is sequentially provided with an intermediate metal layer and a copper layer; and assuming that a thickness of the copper layer is t1, a density of the copper layer is ρ1, a thickness of the intermediate metal layer is t2, a density of the intermediate metal layer is ρ2, a radius of the wire made of an aluminum material is R, and a density of the wire made of an aluminum material is ρ3, t 1 = ( R + t 2 ) 2 + K 1 × ( t 2 2 + 2 ⁢ ⁢ t 2 × R ) ⁢ ⁢ ρ 2 + K 1 × R 2 ⁢ ρ 3 ( 1 - K 1 ) × ρ 1 - R - t 2 , where 0.02≤K1≤0.12. The copper-clad aluminum composite wire can be widely applied to the communication industry.