In overseas high-temperature, high-load and high-dust construction environments, hydraulic oil overheating is one of the most common machinery faults. Most operators cannot quickly locate the cause when equipment power weakens and movements stall. Long-term high-temperature operation accelerates hydraulic oil aging, seal wear and precision valve group damage, greatly increasing overhaul risks. The main causes include blocked heat dissipation systems, mismatched hydraulic oil models and long-term overload operation. Dust accumulation blocks radiators and filters, hindering heat dissipation; inappropriate hydraulic oil viscosity increases system operating load; continuous heavy-duty work causes excessive heat accumulation. Regular cleaning of heat dissipation parts, temperature-adapted hydraulic oil selection and standardized load operation can effectively solve oil temperature abnormalities and stabilize hydraulic performance.