The invention provides a hot forming tool of a 
titanium alloy thin-wall part, comprising five parts, namely stretching equipment, a mould device, a blank, a power supply 
system and a 
temperature control system, wherein the mould device is arranged on a central worktable of the stretching equipment; the blank passes through a side wall crack of the mould device; an insulating and heat-insulation 
cushion layer is used for insulating the blank, a clamp of the stretching equipment, the surface of a mould and a tool of the mould; the power supply 
system is switched on to electrify an 
electrode clamping plate and generate a current in the blank; the blank is heated and the temperature of the blank is measured and controlled by the 
temperature control system; and after the temperature of the blank reaches a target temperature, the part is formed on the surface on the mould by the blank in an adhered manner through carrying out hot 
forming processes successively including stretching, covering, stretching, heat preservation and 
creep deformation and the like on the stretching equipment. A 
machining method of the hot forming tool of the 
titanium alloy thin-wall part comprises eight steps. According to the invention, the 
heating efficiency, the 
process integration, the material formation and the formation precision of the 
titanium alloy thin-wall part in manufacture are greatly improved, so that the hot forming tool of the 
titanium alloy thin-wall part and the 
machining method of the hot forming tool have a practical value and a popularization value.