Based on estimating log outturn of sample trees (in sub-compartment of Larix olgensis plantation prepared for logging operation), the estimating precision of log outturn has improved, the values may find out in the software of Design System of Forest Cutting and Regeneration Design.

The fact that center of gravity and center of figure of a log are not in a same position has been ignored in the process of design, test and investigation of all drum hoists in combined transporters of logs.

According to the technical requirement of the design,we did the functional decomposition and built morphology matrix in design wood chipper,and optimized the design plan by fuzzy assessment.

Based on the problems of traditional disc wood chipper, the method of balanced cutting was put forward, the new typed chipping disc was manufactured.