The invention provides a fixing structure of an engine cylinder internal wire harness 
assembly and a method for fixing the wire harness 
assembly. The fixing structure of the engine cylinder internal wire harness 
assembly comprises the wire harness assembly, a wire harness sheath matched with the wire harness assembly wraps the wire harness assembly, and at least one fixing part is arranged on the wire harness sheath. The wire harness assembly is fixed through the following steps that one end of the wire harness assembly is connected with a 
binding post of an engine cylinder internal oil atomizer through a wire harness terminal, the other end of the wire harness assembly is fixed in a mounting hole in the front end of an engine cylinder cover through an inserting connector, and the fixing parts of the wire harness sheath are fixed to the cylinder cover in sequence in a matching mode. According to the scheme, the assembling and fixing positions of wire harnesses are made to be clear through a reasonable wire harness distribution mode, and the 
design space is utilized effectively; meanwhile, the wire harness sheath performs protecting and guide fixing functions on the wire harnesses, and the performance of resistant to high temperature, resistant to 
corrosion, resistant to vibration and resistant to abrasion is achieved.