Abstract: To direct against the problem of technological process design existing in forestry machinery manufactory at present,this paper discusses that compared with traditional Dimension Chain Method,the Dimension Tracing Method(DTM.) is more perfect in theory,and more scientific in practice.When used in technological process design,the DTM,will raise the efficiency and improve the quality.Taking the process of Type-195 Diesiel's crank shaft as an example,this paper father elucidates the outstanding advantage of the DTM.in selection of technological plan.