Abstract: The structure of mining hydraulic oil tanks is complex,and in the design process,it is easy to focus on the functionality of the tank while neglecting the craftsmanship of tank construction,resulting in difficulties in processing some parts or welding construction in some positions,and even the inability to weld.This makes it difficult for the product to achieve its expected design performance.Therefore,it is necessary to make moderate improvements to certain structures of the oil tank during the first trial production stage of the product to improve manufacturing process.This article mainly describes the process improvements made to the hydraulic oil tank structure of a large mining excavator from two aspects:cutting and welding.