The invention discloses a halogen-free flame-retardant thin-walled oil-resistant cable insulating sheath manufactured by a multi-crosslinking process and a manufacturing method and application thereof. The halogen-free flame-retardant thin-walled oil-resistant cable insulating sheath comprises the following raw materials: an ethylene-vinyl acetate copolymer, rubber, a thermoplastic polyolefin elastomer, a halogen-free flame retardant, a phosphorus based flame retardant, a reinforcing filler, an inorganic functional filler, an organic functional masterbatch, a vulcanizing agent, a vulcanizationaccelerator, an anti-aging agent, a coupling agent, a macromolecular compatibilizer, a lubricant, an anti-oxidant, a nucleating agent, an antistatic agent and a color masterbatch. In the material preparing and cabling process, preparation and cabling of a preset-structured material are realized through physical and chemical crosslinking; manufacture of materials and cables, which have the properties of low smoke, no halogen, flame retardancy, oil resistance, bending resistance, high dimensional stability, wear resistance, stress crack resistance and the like, is realized, the materials and related technologies can be applied to manufacture of robots, intelligent equipment and China Railway High-speed (CRH) cables.