The invention relates to a hydraulic excavator for a mine. The motive power on a hydraulic excavator main body is an anti-explosion diesel engine for a mine, an exhaust device of the anti-explosion diesel engine for the mine is connected with a tail gas cooling water tank through an exhaust connecting pipe, and the tail gas generated by the diesel engine is exhausted out through the tail gas cooling water tank. The hydraulic excavator has the advantages that the starting spark of the engine can be eliminated, the hot tail gas exhausted by the engine can be cooled to the safe temperature, in addition, the poisonous gas is purified, the safety of the underground work is improved, the harm to the physical and mental health of operators in the underground operation caused by the engine tail gas is avoided, the mining efficiency is greatly improved, and the mining cost is effectively reduced.