The utility model provides a urea SCR after-treatment device for a methanol fuel engine. The urea SCR after-treatment device comprises an exhaust pipe, an upstream catalytic device and an SCR catalytic device. The air inlet end of the exhaust pipe is connected with the engine. The air outlet end is sequentially connected with the upstream catalytic device and the SCR catalytic device. The upstream catalytic device comprises a precious metal catalytic device and a metallic oxide catalytic device. A smeared active coating in the precious metal catalytic device is made of precious metal. A smeared active coating in the metallic oxide catalytic device is made of a metallic oxide. The engine comprises the methanol fuel engine, or a blending combustion methanol fuel engine or an engine which adopts exhaust gas recirculation and uses methanol fuel as partial fuel or complete fuel. Due to the design, the poisoning failure of the SCR catalytic device due to methanol and methanal can be avoided, and toxic hydrogen cyanide can not be generated easily.