Abstract: This article described whole strengthening design of nearly 50-year old workshop added 600-ton superheavy-duty crane in detail.After carrying on the comprehensive quality detection and assessment of the original workshop,effective strengthening plan has been proposed by techno-economic verification and optimization of many kinds of reinforcement plans.Mechanical property of strengthened structural elements could meet the requests by computation result of various software computations and manually computing result.Rebirth has been given to the nearly 50-year old workshop.